diff --git a/backend/app/services/post_import_previewer.rb b/backend/app/services/post_import_previewer.rb
index 7052f96..7fa55db 100644
--- a/backend/app/services/post_import_previewer.rb
+++ b/backend/app/services/post_import_previewer.rb
@@ -126,7 +126,7 @@ class PostImportPreviewer
 
     warnings_present = field_warnings.values.any?(&:present?) || base_warnings.present?
     { source_row: row[:source_row],
-      url: normal_url || url,
+      url: validation_errors[:url].present? ? url : (normal_url || url),
       attributes:,
       provenance:,
       tag_sources:,
@@ -199,7 +199,7 @@ class PostImportPreviewer
   def fetch_metadata url
     return { data: { }, warnings: { 'url' => ['URL が空です．'] } } if url.blank?
 
-    data = PostMetadataFetcher.fetch(url).stringify_keys.compact
+    data = sanitise_metadata(PostMetadataFetcher.fetch(url).stringify_keys.compact)
     warnings = { }
     add_field_warning!(warnings, 'title', TITLE_FETCH_WARNING) if data['title'].blank?
     if data['thumbnail_base'].blank?
@@ -215,6 +215,40 @@ class PostImportPreviewer
     { data: { }, warnings: { 'url' => [METADATA_FETCH_WARNING] } }
   end
 
+  def sanitise_metadata metadata
+    {
+        'title' => sanitise_metadata_title(metadata['title']),
+        'thumbnail_base' => sanitise_metadata_url(metadata['thumbnail_base']),
+        'original_created_from' => sanitise_metadata_time(metadata['original_created_from']),
+        'original_created_before' => sanitise_metadata_time(metadata['original_created_before']),
+        'duration' => sanitise_metadata_duration(metadata['duration']),
+        'tags' => metadata['tags'].to_s.presence }.compact
+  end
+
+  def sanitise_metadata_title value
+    value.is_a?(String) ? value.presence : nil
+  end
+
+  def sanitise_metadata_url value
+    return nil unless value.is_a?(String)
+
+    PostUrlNormaliser.normalise(value)
+  end
+
+  def sanitise_metadata_time value
+    return nil unless value.is_a?(String)
+
+    Time.zone.parse(value)&.iso8601
+  rescue ArgumentError, TypeError
+    nil
+  end
+
+  def sanitise_metadata_duration value
+    return nil unless value.is_a?(Numeric)
+
+    value.positive? ? value.to_i : nil
+  end
+
   def preload_metadata! prepared_rows, fetch_metadata, metadata_cache, existing_posts, url_counts
     urls = prepared_rows.filter_map { |row|
       next unless row[:normal_url].present?
diff --git a/frontend/src/components/posts/import/PostImportRowDialog.tsx b/frontend/src/components/posts/import/PostImportRowDialog.tsx
index 4224f66..644b68d 100644
--- a/frontend/src/components/posts/import/PostImportRowDialog.tsx
+++ b/frontend/src/components/posts/import/PostImportRowDialog.tsx
@@ -4,7 +4,7 @@ import FieldWarning from '@/components/common/FieldWarning'
 import FormField from '@/components/common/FormField'
 import PostImportStatusBadge from '@/components/posts/import/PostImportStatusBadge'
 import ThumbnailPreview from '@/components/posts/import/ThumbnailPreview'
-import { effectivePostImportStatus } from '@/components/posts/import/postImportRowStatus'
+import { displayPostImportStatus } from '@/components/posts/import/postImportRowStatus'
 import { Button } from '@/components/ui/button'
 import { Dialog,
 	 DialogContent,
@@ -17,8 +17,7 @@ import { inputClass } from '@/lib/utils'
 import type { FC } from 'react'
 import { useEffect, useState } from 'react'
 
-import type { PostImportOrigin,
-	      PostImportRow } from '@/lib/postImportSession'
+import type { PostImportRow } from '@/lib/postImportSession'
 
 type Draft = {
     url:                   string
@@ -31,41 +30,12 @@ type Draft = {
     parentPostIds:         string }
 
 type Props = {
-    open:         boolean
-    row:          PostImportRow | null
-    saving:       boolean
-    onOpenChange: (open: boolean) => void
-    onSave:       (draft: Draft) => Promise<boolean> }
-
-const originOf = (
-    row:   PostImportRow,
-    field: string,
-): PostImportOrigin =>
-    row.provenance[field] ?? 'automatic'
-
-const changedOrigin = (
-    changed: boolean,
-    row:     PostImportRow,
-    field:   string,
-): PostImportOrigin =>
-    changed ? 'manual' : originOf (row, field)
-
-const originalCreatedOrigin = (
-    row:           PostImportRow,
-    originalDraft: Draft,
-    draft:         Draft,
-): PostImportOrigin => {
-    const changed =
-	originalDraft.originalCreatedFrom !== draft.originalCreatedFrom
-	|| originalDraft.originalCreatedBefore !== draft.originalCreatedBefore
-    if (changed)
-      return 'manual'
-
-    const manualOrigin =
-	originOf (row, 'originalCreatedFrom') === 'manual'
-	|| originOf (row, 'originalCreatedBefore') === 'manual'
-    return manualOrigin ? 'manual' : 'automatic'
-}
+    open:          boolean
+    row:           PostImportRow | null
+    messageRow?:   PostImportRow | null
+    saving:        boolean
+    onOpenChange:  (open: boolean) => void
+    onSave:        (draft: Draft) => Promise<boolean> }
 
 const buildDraft = (row: PostImportRow): Draft => ({
     url: row.url,
@@ -77,6 +47,16 @@ const buildDraft = (row: PostImportRow): Draft => ({
     tags: String (row.attributes.tags ?? ''),
     parentPostIds: String (row.attributes.parentPostIds ?? '') })
 
+const buildResetDraft = (row: PostImportRow): Draft => ({
+    url: row.resetSnapshot.url,
+    title: String (row.resetSnapshot.attributes.title ?? ''),
+    thumbnailBase: String (row.resetSnapshot.attributes.thumbnailBase ?? ''),
+    originalCreatedFrom: String (row.resetSnapshot.attributes.originalCreatedFrom ?? ''),
+    originalCreatedBefore: String (row.resetSnapshot.attributes.originalCreatedBefore ?? ''),
+    duration: String (row.resetSnapshot.attributes.duration ?? ''),
+    tags: String (row.resetSnapshot.attributes.tags ?? ''),
+    parentPostIds: String (row.resetSnapshot.attributes.parentPostIds ?? '') })
+
 const groupedMessages = (
     ...values: Array<string[] | undefined>
 ): string[] =>
@@ -84,7 +64,7 @@ const groupedMessages = (
 
 
 const PostImportRowDialog: FC<Props> = (
-    { open, row, saving, onOpenChange, onSave },
+    { open, row, messageRow, saving, onOpenChange, onSave },
 ) => {
     const [draft, setDraft] = useState<Draft | null> (null)
 
@@ -96,9 +76,7 @@ const PostImportRowDialog: FC<Props> = (
     if (row == null || draft == null)
       return null
 
-    const originalDraft = buildDraft (row)
-    const fieldOrigin = (field: keyof Draft): PostImportOrigin =>
-	changedOrigin (draft[field] !== originalDraft[field], row, field)
+    const displayRow = messageRow ?? row
 
     const update = <Key extends keyof Draft,> (
 	key:   Key,
@@ -131,7 +109,7 @@ const PostImportRowDialog: FC<Props> = (
 		      url={draft.thumbnailBase}
 		      className="h-28 w-28"/>
 		  <div className="flex flex-wrap gap-2">
-		    <PostImportStatusBadge value={effectivePostImportStatus (row)}/>
+		    <PostImportStatusBadge value={displayPostImportStatus (displayRow)}/>
 		  </div>
 		</div>
 
@@ -139,79 +117,78 @@ const PostImportRowDialog: FC<Props> = (
 		  <DialogTextField
 		      label="URL"
 		      value={draft.url}
-		      origin={fieldOrigin ('url')}
-		      warnings={row.fieldWarnings.url}
-		      errors={groupedMessages (row.validationErrors.url, row.importErrors?.url)}
+		      warnings={displayRow.fieldWarnings.url}
+		      errors={groupedMessages (displayRow.validationErrors.url,
+					      displayRow.importErrors?.url)}
 		      onChange={value => update ('url', value)}/>
 		  <DialogTextField
 		      label="タイトル"
 		      value={draft.title}
-		      origin={fieldOrigin ('title')}
-		      warnings={row.fieldWarnings.title}
-		      errors={groupedMessages (row.validationErrors.title, row.importErrors?.title)}
+		      warnings={displayRow.fieldWarnings.title}
+		      errors={groupedMessages (displayRow.validationErrors.title,
+					      displayRow.importErrors?.title)}
 		      onChange={value => update ('title', value)}/>
 		  <DialogTextField
 		      label="サムネール基底 URL"
 		      value={draft.thumbnailBase}
-		      origin={fieldOrigin ('thumbnailBase')}
-		      warnings={row.fieldWarnings.thumbnailBase}
+		      warnings={displayRow.fieldWarnings.thumbnailBase}
 		      errors={groupedMessages (
-			  row.validationErrors.thumbnailBase,
-			  row.importErrors?.thumbnailBase,
+			  displayRow.validationErrors.thumbnailBase,
+			  displayRow.importErrors?.thumbnailBase,
 		      )}
 		      onChange={value => update ('thumbnailBase', value)}/>
 		  <PostOriginalCreatedTimeField
-		      labelAddon={
-			  <PostImportStatusBadge
-			      value={originalCreatedOrigin (row, originalDraft, draft)}/>
-		      }
 		      originalCreatedFrom={draft.originalCreatedFrom || null}
 		      setOriginalCreatedFrom={value => update ('originalCreatedFrom', value ?? '')}
 		      originalCreatedBefore={draft.originalCreatedBefore || null}
 		      setOriginalCreatedBefore={value => update ('originalCreatedBefore', value ?? '')}
 		      errors={groupedMessages (
-			  row.validationErrors.originalCreatedAt,
-			  row.validationErrors.originalCreatedFrom,
-			  row.validationErrors.originalCreatedBefore,
-			  row.importErrors?.originalCreatedAt,
-			  row.importErrors?.originalCreatedFrom,
-			  row.importErrors?.originalCreatedBefore,
+			  displayRow.validationErrors.originalCreatedAt,
+			  displayRow.validationErrors.originalCreatedFrom,
+			  displayRow.validationErrors.originalCreatedBefore,
+			  displayRow.importErrors?.originalCreatedAt,
+			  displayRow.importErrors?.originalCreatedFrom,
+			  displayRow.importErrors?.originalCreatedBefore,
 		      )}/>
 		  <DialogTextField
 		      label="動画時間"
 		      value={draft.duration}
-		      origin={fieldOrigin ('duration')}
 		      errors={groupedMessages (
-			  row.validationErrors.duration,
-			  row.validationErrors.videoMs,
-			  row.importErrors?.duration,
-			  row.importErrors?.videoMs,
+			  displayRow.validationErrors.duration,
+			  displayRow.validationErrors.videoMs,
+			  displayRow.importErrors?.duration,
+			  displayRow.importErrors?.videoMs,
 		      )}
 		      onChange={value => update ('duration', value)}/>
 		  <DialogAreaField
 		      label="タグ"
 		      value={draft.tags}
-		      origin={fieldOrigin ('tags')}
-		      warnings={row.fieldWarnings.tags}
-		      errors={groupedMessages (row.validationErrors.tags, row.importErrors?.tags)}
+		      warnings={displayRow.fieldWarnings.tags}
+		      errors={groupedMessages (displayRow.validationErrors.tags,
+					      displayRow.importErrors?.tags)}
 		      onChange={value => update ('tags', value)}/>
 		  <DialogTextField
 		      label="親投稿"
 		      value={draft.parentPostIds}
-		      origin={fieldOrigin ('parentPostIds')}
 		      errors={groupedMessages (
-			  row.validationErrors.parentPostIds,
-			  row.importErrors?.parentPostIds,
+			  displayRow.validationErrors.parentPostIds,
+			  displayRow.importErrors?.parentPostIds,
 		      )}
 		      onChange={value => update ('parentPostIds', value)}/>
-		  <FieldWarning messages={row.baseWarnings}/>
-		  <FieldError messages={row.validationErrors.base}/>
-		  <FieldError messages={row.importErrors?.base}/>
+		  <FieldWarning messages={displayRow.baseWarnings}/>
+		  <FieldError messages={displayRow.validationErrors.base}/>
+		  <FieldError messages={displayRow.importErrors?.base}/>
 		</div>
 	      </div>
 	    </div>
 
 	    <DialogFooter className="shrink-0 px-6 pb-6 pt-4">
+	      <Button
+		  type="button"
+		  variant="outline"
+		  onClick={() => setDraft (buildResetDraft (row))}>
+		変更をリセット
+	      </Button>
 	      <Button
 		  type="button"
 		  variant="outline"
@@ -230,15 +207,14 @@ const PostImportRowDialog: FC<Props> = (
 }
 
 const DialogTextField = (
-    { label, value, origin, warnings, errors, onChange }: {
+    { label, value, warnings, errors, onChange }: {
 	label:    string
 	value:    string
-	origin:   PostImportOrigin
 	warnings?: string[]
 	errors?:   string[]
 	onChange: (value: string) => void },
 ) => (
-    <FormField label={<DialogLabel label={label} origin={origin}/>} messages={errors}>
+    <FormField label={label} messages={errors}>
       {({ describedBy, invalid }) => (
 	  <>
 	    <input
@@ -252,15 +228,14 @@ const DialogTextField = (
     </FormField>)
 
 const DialogAreaField = (
-    { label, value, origin, warnings, errors, onChange }: {
+    { label, value, warnings, errors, onChange }: {
 	label:    string
 	value:    string
-	origin:   PostImportOrigin
 	warnings?: string[]
 	errors?:   string[]
 	onChange: (value: string) => void },
 ) => (
-    <FormField label={<DialogLabel label={label} origin={origin}/>} messages={errors}>
+    <FormField label={label} messages={errors}>
       {({ describedBy, invalid }) => (
 	  <>
 	    <textarea
@@ -274,14 +249,4 @@ const DialogAreaField = (
 	  </>)}
     </FormField>)
 
-const DialogLabel = (
-    { label, origin }: {
-	label:   string
-	origin:  PostImportOrigin },
-) => (
-    <span className="flex items-center gap-2">
-      <span>{label}</span>
-      <PostImportStatusBadge value={origin}/>
-    </span>)
-
 export default PostImportRowDialog
diff --git a/frontend/src/components/posts/import/PostImportRowSummary.tsx b/frontend/src/components/posts/import/PostImportRowSummary.tsx
index 5f8416e..57f963d 100644
--- a/frontend/src/components/posts/import/PostImportRowSummary.tsx
+++ b/frontend/src/components/posts/import/PostImportRowSummary.tsx
@@ -3,7 +3,7 @@ import { cn } from '@/lib/utils'
 
 import PostImportStatusBadge from '@/components/posts/import/PostImportStatusBadge'
 import ThumbnailPreview from '@/components/posts/import/ThumbnailPreview'
-import { effectivePostImportStatus } from '@/components/posts/import/postImportRowStatus'
+import { displayPostImportStatus } from '@/components/posts/import/postImportRowStatus'
 
 import type { FC } from 'react'
 
@@ -14,22 +14,13 @@ type Props = {
     onEdit:  () => void }
 
 const toneClass = (row: PostImportRow): string[] => {
-    const value = effectivePostImportStatus (row)
+    const value = displayPostImportStatus (row)
     switch (value)
       {
-      case 'created':
-	return [
-	    'border-sky-200 bg-sky-50',
-	    'dark:border-sky-900 dark:bg-sky-950/30']
       case 'skipped':
 	return [
 	    'border-stone-200 bg-stone-50',
 	    'dark:border-stone-800 dark:bg-stone-900/60']
-      case 'failed':
-      case 'error':
-	return [
-	    'border-rose-200 bg-rose-50',
-	    'dark:border-rose-900 dark:bg-rose-950/30']
       case 'warning':
 	return [
 	    'border-amber-200 bg-amber-50',
@@ -63,7 +54,7 @@ const summaryDate = (row: PostImportRow): string =>
 const PostImportRowSummary: FC<Props> = ({ row, onEdit }) => {
     const error = summaryError (row)
     const warning = error == null ? summaryWarning (row) : null
-    const effectiveStatus = effectivePostImportStatus (row)
+    const displayStatus = displayPostImportStatus (row)
 
     return (
 	<>
@@ -104,7 +95,7 @@ const PostImportRowSummary: FC<Props> = ({ row, onEdit }) => {
 		  </div>)}
 	    </div>
 	    <div className="space-y-1">
-	      <PostImportStatusBadge value={effectiveStatus}/>
+	      <PostImportStatusBadge value={displayStatus}/>
 	    </div>
 	    <div className="flex justify-end">
 	      <Button
@@ -134,7 +125,7 @@ const PostImportRowSummary: FC<Props> = ({ row, onEdit }) => {
 		  {row.url}
 		</div>
 		<div className="flex flex-wrap gap-2">
-		  <PostImportStatusBadge value={effectiveStatus}/>
+		  <PostImportStatusBadge value={displayStatus}/>
 		</div>
 		{error && (
 		    <div className="text-xs text-red-700 dark:text-red-200">
diff --git a/frontend/src/components/posts/import/PostImportStatusBadge.tsx b/frontend/src/components/posts/import/PostImportStatusBadge.tsx
index 7556077..fa797e1 100644
--- a/frontend/src/components/posts/import/PostImportStatusBadge.tsx
+++ b/frontend/src/components/posts/import/PostImportStatusBadge.tsx
@@ -10,13 +10,7 @@ type Props = {
 const LABELS: Record<PostImportBadgeValue, string> = {
     ready:     '登録可能',
     warning:   '警告',
-    error:     '要修正',
-    pending:   '未登録',
-    created:   '登録済み',
-    skipped:   'スキップ',
-    failed:    '失敗',
-    automatic: '自動取得',
-    manual:    '手修正' }
+    skipped:   'スキップ' }
 
 const STYLES: Record<PostImportBadgeValue, string[]> = {
     ready: [
@@ -25,27 +19,9 @@ const STYLES: Record<PostImportBadgeValue, string[]> = {
     warning: [
 	'border-amber-300 bg-amber-50 text-amber-700',
 	'dark:border-amber-900 dark:bg-amber-950 dark:text-amber-200'],
-    error: [
-	'border-red-300 bg-red-50 text-red-700',
-	'dark:border-red-900 dark:bg-red-950 dark:text-red-200'],
-    pending: [
-	'border-slate-300 bg-slate-50 text-slate-700',
-	'dark:border-slate-700 dark:bg-slate-900 dark:text-slate-200'],
-    created: [
-	'border-sky-300 bg-sky-50 text-sky-700',
-	'dark:border-sky-900 dark:bg-sky-950 dark:text-sky-200'],
     skipped: [
 	'border-stone-300 bg-stone-50 text-stone-700',
-	'dark:border-stone-700 dark:bg-stone-900 dark:text-stone-200'],
-    failed: [
-	'border-rose-300 bg-rose-50 text-rose-700',
-	'dark:border-rose-900 dark:bg-rose-950 dark:text-rose-200'],
-    automatic: [
-	'border-slate-300 bg-slate-50 text-slate-700',
-	'dark:border-slate-700 dark:bg-slate-900 dark:text-slate-200'],
-    manual: [
-	'border-purple-300 bg-purple-50 text-purple-700',
-	'dark:border-purple-900 dark:bg-purple-950 dark:text-purple-200'] }
+	'dark:border-stone-700 dark:bg-stone-900 dark:text-stone-200'] }
 
 
 const PostImportStatusBadge: FC<Props> = ({ value }) => (
diff --git a/frontend/src/components/posts/import/postImportRowStatus.ts b/frontend/src/components/posts/import/postImportRowStatus.ts
index 7006584..ab91845 100644
--- a/frontend/src/components/posts/import/postImportRowStatus.ts
+++ b/frontend/src/components/posts/import/postImportRowStatus.ts
@@ -1,33 +1,18 @@
-import type { PostImportOrigin,
-	      PostImportRow } from '@/lib/postImportSession'
+import type { PostImportRow } from '@/lib/postImportSession'
 
-export type PostImportEffectiveStatus =
-    'created'
-    | 'skipped'
-    | 'failed'
-    | 'error'
-    | 'warning'
-    | 'ready'
+export type PostImportDisplayStatus = 'ready' | 'warning' | 'skipped'
 
-export type PostImportBadgeValue =
-    PostImportEffectiveStatus
-    | 'pending'
-    | PostImportOrigin
+export type PostImportBadgeValue = PostImportDisplayStatus
 
+const hasWarnings = (row: PostImportRow): boolean =>
+    Object.values (row.fieldWarnings ?? { }).some (_1 => _1.length > 0)
+    || row.baseWarnings.length > 0
 
-export const effectivePostImportStatus = (
+export const displayPostImportStatus = (
     row: PostImportRow,
-): PostImportEffectiveStatus => {
-    if (Object.keys (row.validationErrors ?? { }).length > 0)
-      return 'error'
-
-    switch (row.importStatus)
-      {
-      case 'created':
-      case 'skipped':
-      case 'failed':
-	return row.importStatus
-      default:
-	return row.status
-      }
-}
+): PostImportDisplayStatus =>
+    row.skipReason === 'existing' || row.importStatus === 'skipped'
+    ? 'skipped'
+    : hasWarnings (row)
+    ? 'warning'
+    : 'ready'
diff --git a/frontend/src/lib/postImportRows.ts b/frontend/src/lib/postImportRows.ts
index f73bfd7..3998e28 100644
--- a/frontend/src/lib/postImportRows.ts
+++ b/frontend/src/lib/postImportRows.ts
@@ -16,6 +16,10 @@ const rowChanged = (
     || JSON.stringify (previous.provenance) !== JSON.stringify (next.provenance)
     || JSON.stringify (previous.tagSources ?? { }) !== JSON.stringify (next.tagSources ?? { })
 
+const buildResetSnapshot = (row: PostImportRow) => ({
+    url: row.url,
+    attributes: row.attributes })
+
 
 export const processableImportRows = (rows: PostImportRow[]): PostImportRow[] =>
     rows.filter (row => {
@@ -111,7 +115,11 @@ export const mergeValidatedImportRows = (
 		: previous.baseWarnings,
 	    validationErrors: row.validationErrors,
 	    status: row.status,
-	    metadataUrl: row.metadataUrl }
+	    metadataUrl: row.metadataUrl,
+	    resetSnapshot:
+		row.metadataUrl !== previous.metadataUrl
+		? buildResetSnapshot (row)
+		: previous.resetSnapshot }
     })
 }
 
@@ -154,6 +162,7 @@ export const mergePreviewImportRows = (
 	    tagSources: mergedTagSources,
 	    skipReason: row.skipReason,
 	    existingPostId: row.existingPostId,
+	    resetSnapshot: row.resetSnapshot,
 	    createdPostId: previous.createdPostId,
 	    importStatus: previous.importStatus,
 	    importErrors: previous.importErrors }
@@ -214,3 +223,8 @@ export const retryImportRow = (
 	row.sourceRow === sourceRow && row.importStatus === 'failed'
 	? { ...row, importStatus: 'pending', importErrors: undefined }
 	: row)
+
+export const initialisePreviewRows = (rows: PostImportRow[]): PostImportRow[] =>
+    rows.map (row => ({
+	...row,
+	resetSnapshot: buildResetSnapshot (row) }))
diff --git a/frontend/src/lib/postImportStorage.ts b/frontend/src/lib/postImportStorage.ts
index da42709..d355e9e 100644
--- a/frontend/src/lib/postImportStorage.ts
+++ b/frontend/src/lib/postImportStorage.ts
@@ -1,4 +1,5 @@
 import type { PostImportOrigin,
+	      PostImportResetSnapshot,
 	      PostImportRow,
 	      PostImportSession,
 	      PostImportStatus,
@@ -137,6 +138,24 @@ const hasOnlyKeys = (
 ): boolean =>
     Object.keys (value).every (key => allowedKeys.includes (key))
 
+const sanitiseResetSnapshot = (value: unknown): PostImportResetSnapshot | null => {
+    if (!(isPlainObject (value)))
+      return null
+    if (typeof value.url !== 'string')
+      return null
+    if (!(isPlainObject (value.attributes)))
+      return null
+    if (!(hasOnlyKeys (value.attributes, ATTRIBUTE_KEYS)))
+      return null
+    if (!(Object.values (value.attributes).every (entry =>
+	typeof entry === 'string' || typeof entry === 'number')))
+      return null
+
+    return {
+	url: value.url,
+	attributes: value.attributes as Record<string, string | number> }
+}
+
 
 const sanitiseRow = (value: unknown): PostImportRow | null => {
     if (!(isPlainObject (value)))
@@ -166,8 +185,11 @@ const sanitiseRow = (value: unknown): PostImportRow | null => {
 
     const validationErrors = ensureStringListRecord (value.validationErrors)
     const fieldWarnings = ensureStringListRecord (value.fieldWarnings)
+    const resetSnapshot = sanitiseResetSnapshot (value.resetSnapshot)
     if (validationErrors == null || fieldWarnings == null)
       return null
+    if (resetSnapshot == null)
+      return null
 
     const importErrors =
 	value.importErrors == null
@@ -215,6 +237,7 @@ const sanitiseRow = (value: unknown): PostImportRow | null => {
 	existingPostId:
 	    isPositiveInteger (value.existingPostId) ? Number (value.existingPostId) : undefined,
 	metadataUrl: typeof value.metadataUrl === 'string' ? value.metadataUrl : undefined,
+	resetSnapshot,
 	createdPostId:
 	    isPositiveInteger (value.createdPostId) ? Number (value.createdPostId) : undefined,
 	importStatus: value.importStatus }
diff --git a/frontend/src/lib/postImportTypes.ts b/frontend/src/lib/postImportTypes.ts
index 7b5b4b9..420483e 100644
--- a/frontend/src/lib/postImportTypes.ts
+++ b/frontend/src/lib/postImportTypes.ts
@@ -9,6 +9,10 @@ export type PostImportSkipReason = 'existing'
 export type PostImportResultStatus = 'created' | 'skipped' | 'failed'
 export type PostImportAttributeValue = string | number
 
+export type PostImportResetSnapshot = {
+    url:        string
+    attributes: Record<string, PostImportAttributeValue> }
+
 export type PostImportRow = {
     sourceRow:         number
     url:               string
@@ -23,6 +27,7 @@ export type PostImportRow = {
     skipReason?:       PostImportSkipReason
     existingPostId?:   number
     metadataUrl?:      string
+    resetSnapshot:     PostImportResetSnapshot
     createdPostId?:    number
     importStatus?:     PostImportStatus }
 
diff --git a/frontend/src/pages/posts/PostImportResultPage.tsx b/frontend/src/pages/posts/PostImportResultPage.tsx
index 08d026c..e8aec41 100644
--- a/frontend/src/pages/posts/PostImportResultPage.tsx
+++ b/frontend/src/pages/posts/PostImportResultPage.tsx
@@ -8,13 +8,14 @@ import PageTitle from '@/components/common/PageTitle'
 import PrefetchLink from '@/components/PrefetchLink'
 import MainArea from '@/components/layout/MainArea'
 import PostImportStatusBadge from '@/components/posts/import/PostImportStatusBadge'
-import { effectivePostImportStatus } from '@/components/posts/import/postImportRowStatus'
+import { displayPostImportStatus } from '@/components/posts/import/postImportRowStatus'
 import { Button } from '@/components/ui/button'
 import { toast } from '@/components/ui/use-toast'
 import { SITE_TITLE } from '@/config'
 import { apiPost } from '@/lib/api'
 import { canEditContent } from '@/lib/users'
 import { clearPostImportSourceDraft,
+	 initialisePreviewRows,
 	 loadPostImportSession,
 	 mergeImportResults,
 	 mergeValidatedImportRows,
@@ -33,7 +34,7 @@ import type { User } from '@/types'
 type Props = { user: User | null }
 
 const resultToneClass = (
-    status: ReturnType<typeof effectivePostImportStatus>,
+    status: 'created' | 'failed' | 'invalid' | 'skipped' | 'warning' | 'ready',
 ): string[] => {
     switch (status)
       {
@@ -46,7 +47,10 @@ const resultToneClass = (
 	    'border-stone-200 bg-stone-50',
 	    'dark:border-stone-800 dark:bg-stone-900/60']
       case 'failed':
-      case 'error':
+	return [
+	    'border-rose-200 bg-rose-50',
+	    'dark:border-rose-900 dark:bg-rose-950/30']
+      case 'invalid':
 	return [
 	    'border-rose-200 bg-rose-50',
 	    'dark:border-rose-900 dark:bg-rose-950/30']
@@ -117,7 +121,9 @@ const PostImportResultPage: FC<Props> = ({ user }) => {
 			tagSources: row.tagSources,
 			metadataUrl: row.metadataUrl })),
 		changed_row: -1 })
-	    const validatedRows = mergeValidatedImportRows (pendingRows, validated.rows)
+	    const validatedRows = mergeValidatedImportRows (
+		pendingRows,
+		initialisePreviewRows (validated.rows))
 	    setSession (current =>
 		current
 		? { ...current, rows: validatedRows }
@@ -198,28 +204,44 @@ const PostImportResultPage: FC<Props> = ({ user }) => {
 	    <div className="rounded-lg border bg-white p-4 dark:border-neutral-700
 			    dark:bg-neutral-900">
 	      <div className="flex flex-wrap gap-2">
-		<SummaryChip label="登録成功" value={counts.created} badge="created"/>
+		<SummaryChip label="登録成功" value={counts.created}/>
 		<SummaryChip label="スキップ" value={counts.skipped} badge="skipped"/>
-		<SummaryChip label="失敗" value={counts.failed} badge="failed"/>
-		<SummaryChip label="要修正" value={counts.invalid} badge="error"/>
+		<SummaryChip label="失敗" value={counts.failed}/>
+		<SummaryChip label="要修正" value={counts.invalid}/>
 	      </div>
 	    </div>
 
 	    <div className="space-y-3">
 	      {session.rows.map (row => {
-		  const status = effectivePostImportStatus (row)
+		  const displayStatus =
+		      Object.keys (row.validationErrors).length > 0
+		      ? 'invalid'
+		      : row.importStatus === 'created'
+		      ? 'created'
+		      : row.importStatus === 'failed'
+		      ? 'failed'
+		      : displayPostImportStatus (row)
+		  const canEdit =
+		      Object.keys (row.validationErrors).length > 0
+		      || row.importStatus === 'failed'
+		  const canRetry =
+		      row.importStatus === 'created'
+		      ? false
+		      : row.importStatus === 'failed'
+		      && Object.keys (row.validationErrors).length === 0
 		  return (
 		  <div
 		      key={row.sourceRow}
 		      className={[
 			  'rounded-lg border p-4',
-			  ...resultToneClass (status)].join (' ')}>
+			  ...resultToneClass (displayStatus)].join (' ')}>
 		    <div className="flex flex-col gap-3 md:flex-row md:items-start
 				    md:justify-between">
 		      <div className="space-y-2">
 			<div className="flex flex-wrap items-center gap-2">
 			  <span className="text-sm font-medium">行 {row.sourceRow}</span>
-			  <PostImportStatusBadge value={status}/>
+			  {displayStatus === 'skipped' && (
+			      <PostImportStatusBadge value="skipped"/>)}
 			</div>
 			<div className="text-sm text-neutral-700 dark:text-neutral-200">
 			  {String (row.attributes.title ?? '') || row.url}
@@ -238,14 +260,14 @@ const PostImportResultPage: FC<Props> = ({ user }) => {
 				投稿を開く
 			      </PrefetchLink>
 			    </Button>)}
-			{(status === 'error' || row.importStatus === 'failed') && (
+			{canEdit && (
 			    <Button
 				type="button"
 				variant="outline"
 				onClick={() => openRepair (row.sourceRow)}>
 			      編輯
 			    </Button>)}
-			{row.importStatus === 'failed' && status !== 'error' && (
+			{canRetry && (
 			    <>
 			      <Button
 				  type="button"
@@ -293,11 +315,11 @@ const SummaryChip = (
     { label, value, badge }: {
 	label: string
 	value: number
-	badge: 'created' | 'skipped' | 'failed' | 'error' },
+	badge?: 'skipped' },
 ) => (
     <div className="flex items-center gap-2 rounded-full border border-border
 		    bg-background px-3 py-1 text-sm">
-      <PostImportStatusBadge value={badge}/>
+      {badge && <PostImportStatusBadge value={badge}/>}
       <span>{label} {value}</span>
     </div>)
 
diff --git a/frontend/src/pages/posts/PostImportReviewPage.tsx b/frontend/src/pages/posts/PostImportReviewPage.tsx
index 6bbcdb0..2c7a3ca 100644
--- a/frontend/src/pages/posts/PostImportReviewPage.tsx
+++ b/frontend/src/pages/posts/PostImportReviewPage.tsx
@@ -16,6 +16,7 @@ import { apiPost } from '@/lib/api'
 import { canEditContent } from '@/lib/users'
 import { loadPostImportSession,
 	 creatableImportRows,
+	 initialisePreviewRows,
 	 mergeImportResults,
 	 mergeValidatedImportRows,
 	 processableImportRows,
@@ -53,6 +54,7 @@ const PostImportReviewPage: FC<Props> = ({ user }) => {
     const [loading, setLoading] = useState (false)
     const [missing, setMissing] = useState (false)
     const [savingRow, setSavingRow] = useState<number | null> (null)
+    const [dialogMessageRow, setDialogMessageRow] = useState<PostImportRow | null> (null)
 
     useEffect (() => {
 	if (sessionId == null)
@@ -102,6 +104,16 @@ const PostImportReviewPage: FC<Props> = ({ user }) => {
 	element?.scrollIntoView ({ block: 'center', behavior: 'smooth' })
     }, [editingRow, session?.repairMode])
 
+    useEffect (() => {
+	if (editingRow == null)
+	  {
+	    setDialogMessageRow (null)
+	    return
+	  }
+	if (dialogMessageRow?.sourceRow !== editingRow.sourceRow)
+	  setDialogMessageRow (null)
+    }, [editingRow, dialogMessageRow])
+
     const updateSessionRows = (nextRows: PostImportRow[]) =>
 	setSession (current =>
 	    current ? { ...current, rows: nextRows } : current)
@@ -171,7 +183,15 @@ const PostImportReviewPage: FC<Props> = ({ user }) => {
 			tagSources: row.tagSources,
 			metadataUrl: row.metadataUrl })),
 		changed_row: urlChanged ? editingRow.sourceRow : -1 })
-	    updateSessionRows (mergeValidatedImportRows (nextRows, validated.rows))
+	    const validatedRows = initialisePreviewRows (validated.rows)
+	    const target = validatedRows.find (row => row.sourceRow === editingRow.sourceRow)
+	    if (target != null && Object.keys (target.validationErrors).length > 0)
+	      {
+		setDialogMessageRow (target)
+		return false
+	      }
+	    updateSessionRows (mergeValidatedImportRows (nextRows, validatedRows))
+	    setDialogMessageRow (null)
 	    setSearchParams ({ })
 	    return true
 	}
@@ -193,19 +213,41 @@ const PostImportReviewPage: FC<Props> = ({ user }) => {
 	setLoading (true)
 	try
 	{
+	    const validated = await apiPost<{ rows: PostImportRow[] }> ('/posts/import/validate', {
+		rows: session.rows
+		    .filter (row => row.importStatus !== 'created')
+		    .map (row => ({
+			sourceRow: row.sourceRow,
+			url: row.url,
+			attributes: row.attributes,
+			provenance: row.provenance,
+			tagSources: row.tagSources,
+			metadataUrl: row.metadataUrl })),
+		changed_row: -1 })
+	    const validatedRows = initialisePreviewRows (validated.rows)
+	    const mergedRows = mergeValidatedImportRows (session.rows, validatedRows)
+	    const firstInvalid = mergedRows.find (row => Object.keys (row.validationErrors).length > 0)
+	    if (firstInvalid != null)
+	      {
+		setSession ({ ...session, rows: mergedRows })
+		setDialogMessageRow (firstInvalid)
+		setSearchParams ({ edit: String (firstInvalid.sourceRow) })
+		return
+	      }
+
 	    const result = await apiPost<{
 		created: number
 		skipped: number
 		failed:  number
 		rows:    PostImportResultRow[] }> ('/posts/import', {
-		    rows: processable.map (row => ({
+		    rows: processableImportRows (mergedRows).map (row => ({
 			sourceRow: row.sourceRow,
 			url: row.url,
 			attributes: row.attributes,
 			provenance: row.provenance,
 			tagSources: row.tagSources,
 			metadataUrl: row.metadataUrl })) })
-	    const nextRows = mergeImportResults (session.rows, result.rows)
+	    const nextRows = mergeImportResults (mergedRows, result.rows)
 	    const nextSession = { ...session, rows: nextRows, repairMode: 'all' as const }
 	    setSession (nextSession)
 	    const saved = savePostImportSession (sessionId, nextSession, message =>
@@ -256,10 +298,8 @@ const PostImportReviewPage: FC<Props> = ({ user }) => {
 		<div className="flex flex-wrap items-center gap-2">
 		  <SummaryChip label="全件" value={counts.total}/>
 		  <SummaryChip label="登録対象" value={counts.submittable}/>
-		  <SummaryChip label="要修正" value={counts.invalid}/>
+		  <SummaryChip label="要確認" value={counts.invalid}/>
 		  <SummaryChip label="スキップ予定" value={counts.skipPlanned}/>
-		  <SummaryChip label="登録済み" value={counts.created}/>
-		  <SummaryChip label="失敗" value={counts.failed}/>
 		</div>
 	      </div>
 
@@ -288,9 +328,10 @@ const PostImportReviewPage: FC<Props> = ({ user }) => {
 	  <PostImportRowDialog
 	      open={editingRow != null}
 	      row={editingRow}
+	      messageRow={dialogMessageRow}
 	      saving={savingRow != null}
 	      onOpenChange={open => {
-		  if (!(open))
+		  if (!open)
 		    setSearchParams ({ })
 	      }}
 	      onSave={saveDraft}/>
@@ -319,14 +360,12 @@ const PostImportFooter = (
       <div className="mx-auto flex max-w-6xl flex-col gap-3 md:flex-row
 		      md:items-center md:justify-between">
 	<div className="flex flex-wrap items-center gap-2 text-sm">
-	  <PostImportStatusBadge value="pending"/>
 	  <span>処理対象 {processableCount} 件</span>
 	  <PostImportStatusBadge value="ready"/>
 	  <span>登録対象 {creatableCount} 件</span>
 	  <PostImportStatusBadge value="skipped"/>
 	  <span>スキップ予定 {skipPlannedCount} 件</span>
-	  <PostImportStatusBadge value="error"/>
-	  <span>要修正 {invalidCount} 件</span>
+	  <span>要確認 {invalidCount} 件</span>
 	</div>
 	<div className="flex flex-col gap-2 sm:flex-row">
 	  <Button type="button" variant="outline" onClick={onBack}>
diff --git a/frontend/src/pages/posts/PostImportSourcePage.tsx b/frontend/src/pages/posts/PostImportSourcePage.tsx
index ad95f90..2cc8bac 100644
--- a/frontend/src/pages/posts/PostImportSourcePage.tsx
+++ b/frontend/src/pages/posts/PostImportSourcePage.tsx
@@ -15,6 +15,7 @@ import { inputClass } from '@/lib/utils'
 import { countImportSourceLines,
 	 cleanupExpiredPostImportSessions,
 	 createPostImportSessionId,
+	 initialisePreviewRows,
 	 loadPostImportSourceDraft,
 	 savePostImportSession,
 	 savePostImportSourceDraft,
@@ -115,7 +116,7 @@ const PostImportSourcePage: FC<Props> = ({ user }) => {
 	    const sessionId = createPostImportSessionId ()
 	    const saved = savePostImportSession (sessionId, {
 		source,
-		rows: data.rows,
+		rows: initialisePreviewRows (data.rows),
 		repairMode: 'all' }, message =>
 		toast ({ title: '取込状態を保存できませんでした', description: message }))
 	    if (!(saved))