diff --git a/backend/app/controllers/counts_exports_controller.rb b/backend/app/controllers/counts_exports_controller.rb
index ca459ad..537d512 100644
--- a/backend/app/controllers/counts_exports_controller.rb
+++ b/backend/app/controllers/counts_exports_controller.rb
@@ -9,6 +9,14 @@ class CountsExportsController < ApplicationController
     token = CountsExportDownload.prepare(exporter, session[:counts_export_owner])
     response.headers['Cache-Control'] = 'private, no-store'
     render json: { token: }
+  rescue CountsExportDownload::Busy
+    head :too_many_requests
+  rescue CountsExportDownload::TooLarge
+    head 413
+  rescue CountsExportDownload::TimedOut
+    head :gateway_timeout
+  rescue CountsExportDownload::StorageFull, Errno::ENOSPC
+    head :insufficient_storage
   rescue ArgumentError, TypeError, KeyError, JSON::ParserError
     head :bad_request
   end
diff --git a/backend/app/services/counts_export_download.rb b/backend/app/services/counts_export_download.rb
index 0dbbd74..b773c5c 100644
--- a/backend/app/services/counts_export_download.rb
+++ b/backend/app/services/counts_export_download.rb
@@ -4,23 +4,70 @@ require 'fileutils'
 # Finish generation before reporting readiness; downloads never hold the full file in RAM.
 class CountsExportDownload
   EXPIRY = 10.minutes
+  MAX_CONCURRENT_EXPORTS = 2
+  MAX_FILE_BYTES = 128.megabytes
+  MAX_STORED_BYTES = 512.megabytes
+  MAX_EXPORT_SECONDS = 120
+  class Busy < StandardError; end
+  class TooLarge < StandardError; end
+  class TimedOut < StandardError; end
+  class StorageFull < StandardError; end
 
   def self.directory = Rails.root.join('tmp', 'counts_exports')
   def self.verifier = Rails.application.message_verifier('counts_export_download')
 
   def self.prepare(exporter, owner)
+    FileUtils.mkdir_p(directory, mode: 0o700)
+    slot = acquire_slot
+
+    begin
+      generate(exporter, owner)
+    ensure
+      slot.close
+    end
+  end
+
+  def self.acquire_slot
+    MAX_CONCURRENT_EXPORTS.times do |index|
+      path = directory.join(".slot-#{ index }.lock")
+      handle = File.open(path, File::RDWR | File::CREAT, 0o600)
+      return handle if handle.flock(File::LOCK_EX | File::LOCK_NB)
+
+      handle.close
+    end
+    raise Busy
+  end
+
+  def self.generate(exporter, owner)
     FileUtils.mkdir_p(directory, mode: 0o700)
     Dir.glob(directory.join('counts-*.export')).each do |path|
       File.unlink(path) if File.mtime(path) < Time.current - EXPIRY
     rescue Errno::ENOENT
       # Another request may have removed an expired download.
     end
+    stored = Dir.glob(directory.join('counts-*')).sum do |path|
+      File.size(path)
+    rescue Errno::ENOENT
+      0
+    end
+    reserved = MAX_CONCURRENT_EXPORTS * MAX_FILE_BYTES
+    raise StorageFull if stored + reserved > MAX_STORED_BYTES
+
     file = Tempfile.create(['counts-', '.part'], directory)
     complete = false
+    bytes = 0
+    deadline = Process.clock_gettime(Process::CLOCK_MONOTONIC) + MAX_EXPORT_SECONDS
     path = file.path
     begin
       file.binmode
-      exporter.body.each { file.write(_1) }
+      exporter.body.each do |chunk|
+        raise TimedOut if Process.clock_gettime(Process::CLOCK_MONOTONIC) > deadline
+
+        bytes += chunk.bytesize
+        raise TooLarge if bytes > MAX_FILE_BYTES
+
+        file.write(chunk)
+      end
       file.close
       finished_path = path.sub(/\.part\z/, '.export')
       File.rename(path, finished_path)
diff --git a/frontend/src/components/common/SortableItem.tsx b/frontend/src/components/common/SortableItem.tsx
index ada6307..a57c346 100644
--- a/frontend/src/components/common/SortableItem.tsx
+++ b/frontend/src/components/common/SortableItem.tsx
@@ -9,9 +9,9 @@ import type { ReactNode } from 'react'
 type Name = { text: string; language: string }
 
 
-const SortableItem = ({ id, name, fixed, children, moveGroup }: {
+const SortableItem = ({ id, name, fixed, children, moveGroup, handleId }: {
     id: string; name: Name; fixed?: boolean; children: ReactNode
-    moveGroup: (direction: number) => void },
+    moveGroup: (direction: number) => void; handleId: string },
 ) => {
   const motion = useClientMotion ()
   const item = useSortable ({ id, disabled: fixed,
@@ -25,15 +25,16 @@ const SortableItem = ({ id, name, fixed, children, moveGroup }: {
           item.isDragging && 'opacity-30 ring-2 ring-blue-500 dark:ring-blue-400')}>
     <div className="flex min-w-0 items-start gap-1 px-1">
       {fixed ? <span className="w-6 shrink-0"/> : <button type="button"
-          ref={item.setActivatorNodeRef} {...item.attributes} {...item.listeners}
+	  id={handleId} ref={item.setActivatorNodeRef} {...item.attributes} {...item.listeners}
           aria-label={name.text} lang={name.language}
-          aria-keyshortcuts="Space ArrowUp ArrowDown ArrowLeft ArrowRight Enter Escape"
+	  aria-keyshortcuts="Space ArrowUp ArrowDown Enter Escape Alt+ArrowLeft Alt+ArrowRight"
           className="mt-1 w-6 shrink-0 cursor-grab touch-none rounded
           focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-blue-500
           active:cursor-grabbing dark:focus-visible:ring-blue-400"
           onClick={event => event.stopPropagation ()}
           onKeyDown={event => {
-            if (event.altKey && ['ArrowLeft', 'ArrowRight'].includes (event.key))
+	    if (event.altKey && !item.isDragging
+		&& ['ArrowLeft', 'ArrowRight'].includes (event.key))
             {
               event.preventDefault ()
               event.stopPropagation ()
diff --git a/frontend/src/components/common/SortableList.tsx b/frontend/src/components/common/SortableList.tsx
index 9801c4a..d57d19d 100644
--- a/frontend/src/components/common/SortableList.tsx
+++ b/frontend/src/components/common/SortableList.tsx
@@ -2,7 +2,7 @@ import { DndContext, DragOverlay, KeyboardSensor, MouseSensor, TouchSensor,
          closestCenter, useDroppable, useSensor, useSensors } from '@dnd-kit/core'
 import { SortableContext, arrayMove, rectSortingStrategy,
          sortableKeyboardCoordinates } from '@dnd-kit/sortable'
-import { useState } from 'react'
+import { useId, useRef, useState } from 'react'
 import { createPortal } from 'react-dom'
 
 import SortableItem from '@/components/common/SortableItem'
@@ -30,6 +30,9 @@ const SortableList = ({ groups, name, renderItem, renderGroup, onChange, fixed =
     onChange: (groups: Groups) => void; fixed?: string[] },
 ) => {
   const [preview, setPreview] = useState<Groups | null> (null)
+  const previewRef = useRef<Groups | null> (null)
+  const lastOver = useRef<string | null> (null)
+  const scope = useId ()
   const [active, setActive] = useState<string | null> (null)
   const motion = useClientMotion ()
   const current = preview ?? groups
@@ -47,22 +50,33 @@ const SortableList = ({ groups, name, renderItem, renderGroup, onChange, fixed =
     if (source === target)
     {
       const from = value[source].indexOf (id)
-      const to = over.startsWith ('group:') ? value[target].length - 1 : value[target].indexOf (over)
+      const to = over.startsWith ('group:')
+	  ? value[target].length - 1 : value[target].indexOf (over)
       if (from === to || to < 0) return value
       return { ...value, [source]: arrayMove (value[source], from, to) }
     }
     const destination = value[target].filter (item => item !== id)
     const position = destination.indexOf (over)
     destination.splice (position < 0 ? destination.length : position, 0, id)
-    return { ...value, [source]: value[source].filter (item => item !== id), [target]: destination }
+    return { ...value, [source]: value[source].filter (item => item !== id),
+	[target]: destination }
   }
   const moveGroup = (id: string, direction: number) => {
     const keys = Object.keys (groups)
     const group = owner (id, groups)
     const target = keys[keys.indexOf (group ?? '') + direction]
-    if (target != null) onChange (relocate (groups, id, `group:${target}`))
+    if (target != null)
+    {
+      onChange (relocate (groups, id, `group:${target}`))
+      requestAnimationFrame (() => document.getElementById (`${scope}-${id}`)?.focus ())
+    }
+  }
+  const reset = () => {
+    previewRef.current = null
+    lastOver.current = null
+    setPreview (null)
+    setActive (null)
   }
-  const reset = () => { setPreview (null); setActive (null) }
   return <DndContext sensors={sensors} collisionDetection={closestCenter}
       accessibility={{ announcements: {
           onDragStart: event => name (String (event.active.id)).text,
@@ -72,19 +86,37 @@ const SortableList = ({ groups, name, renderItem, renderGroup, onChange, fixed =
           onDragMove: () => undefined, onDragEnd: () => undefined,
           onDragCancel: () => undefined },
           screenReaderInstructions: { draggable: active == null ? '' : name (active).text } }}
-      onDragStart={event => { setPreview (groups); setActive (String (event.active.id)) }}
-      onDragOver={event => {
+      onDragStart={event => {
+	previewRef.current = groups
+	lastOver.current = null
+	setPreview (groups)
+	setActive (String (event.active.id))
+      }} onDragOver={event => {
         if (event.over == null || event.active.id === event.over.id) return
-        setPreview (previous => relocate (
-            previous ?? groups, String (event.active.id), String (event.over!.id)))
+	const target = String (event.over.id)
+	if (lastOver.current === target) return
+	const next = relocate (previewRef.current ?? groups, String (event.active.id), target)
+	previewRef.current = next
+	lastOver.current = target
+	setPreview (next)
       }} onDragCancel={reset} onDragEnd={event => {
-        if (event.over != null && preview != null) onChange (preview)
+	if (event.over != null)
+	{
+	  const id = String (event.active.id)
+	  const target = String (event.over.id)
+	  const latest = previewRef.current ?? groups
+	  const next = (target === id || target === lastOver.current)
+	      ? latest : relocate (latest, id, target)
+	  onChange (next)
+	}
         reset ()
       }}>
+
     {Object.entries (current).map (([group, ids]) => <div key={group}>
       {renderGroup (group, <SortableContext items={ids} strategy={rectSortingStrategy}>
         <Group id={group}>{ids.map (id => <SortableItem key={id} id={id}
-            name={name (id)} fixed={fixed.includes (id)} moveGroup={direction => moveGroup (id, direction)}>
+	    name={name (id)} fixed={fixed.includes (id)} handleId={`${scope}-${id}`}
+	    moveGroup={direction => moveGroup (id, direction)}>
           {renderItem (id, group)}
         </SortableItem>)}</Group>
       </SortableContext>)}
diff --git a/frontend/src/components/counts/CountsControls.tsx b/frontend/src/components/counts/CountsControls.tsx
index 3559750..a40c3ff 100644
--- a/frontend/src/components/counts/CountsControls.tsx
+++ b/frontend/src/components/counts/CountsControls.tsx
@@ -9,7 +9,7 @@ import FormField from '@/components/common/FormField'
 import HelpPopover from '@/components/common/HelpPopover'
 import TagInput from '@/components/common/TagInput'
 import { Button } from '@/components/ui/button'
-import { normaliseCountsParams } from '@/lib/counts'
+import { countsUseLatest, normaliseCountsParams } from '@/lib/counts'
 import { useClientMotion } from '@/lib/useClientMotion'
 import { inputClass } from '@/lib/utils'
 import { useUITranslation } from '@/lib/useUITranslation'
@@ -20,11 +20,13 @@ import type { CountsResource } from '@/lib/counts'
 
 
 const CountsControls = (
-    { resource, applied, open, setOpen, execute, displayJSON, reorder, actions }: {
+    { resource, applied, open, setOpen, execute, displayJSON, displayRowNumbers,
+      reorder, actions }: {
         resource: CountsResource; applied: URLSearchParams; open: boolean
         setOpen: (open: boolean) => void
         execute: (params: URLSearchParams) => void
         displayJSON: (enabled: boolean) => void
+	displayRowNumbers: (enabled: boolean) => void
         reorder: (value: string) => void; actions?: ReactNode },
 ) => {
   const { label, message } = useUITranslation ('counts')
@@ -33,17 +35,19 @@ const CountsControls = (
   const [draft, setDraft] = useState (() => new URLSearchParams (applied))
   const order = applied.get ('order')
   const nestedJSON = applied.get ('nested_json')
+  const rowNumbers = applied.get ('row_numbers')
   useEffect (() => {
     setDraft (previous => {
       const next = new URLSearchParams (previous)
-      for (const [key, value] of Object.entries ({ order, nested_json: nestedJSON }))
+      const display = { order, nested_json: nestedJSON, row_numbers: rowNumbers }
+      for (const [key, value] of Object.entries (display))
       {
         if (value == null) next.delete (key)
         else next.set (key, value)
       }
       return next
     })
-  }, [order, nestedJSON])
+  }, [order, nestedJSON, rowNumbers])
   const mode = draft.get ('mode') ?? 'summary'
   const history = draft.get ('definition') === 'history'
   const update = (key: string, value: string) => setDraft (previous => {
@@ -66,13 +70,18 @@ const CountsControls = (
           {label (key)}<DateTimeField precision="second" value={draft.get (key) ?? ''}
               aria-label={message (key).text} onChange={value => update (key, value ?? '')}/>
         </label>)}
-      </> : <label className="flex flex-wrap items-center gap-1 text-sm">
+      </> : <div className="flex flex-wrap items-center gap-1 text-sm">
         {label ('referenceAt')}<HelpPopover label={message ('referenceAt')}>
           {label ('referenceHelp')}</HelpPopover>
-        <DateTimeField precision="second" value={draft.get ('at') ?? ''}
-            aria-label={message ('referenceAt').text}
+	<label className="inline-flex items-center gap-1">
+	  <input type="checkbox" checked={countsUseLatest (draft)}
+	      onChange={event => update ('current', event.target.checked ? '1' : '0')}/>
+	  {label ('latest')}</label>
+	<DateTimeField precision="second" disabled={countsUseLatest (draft)}
+	    value={draft.get ('at') ?? ''}
+	    aria-label={message ('referenceAt').text} lang={message ('referenceAt').language}
             onChange={value => update ('at', value ?? '')}/>
-      </label>}
+      </div>}
     </div>
     <div className="flex flex-wrap items-center gap-2 border-b py-1 dark:border-slate-700">
       <Button type="submit" size="sm">{label ('run')}</Button>
@@ -87,7 +96,14 @@ const CountsControls = (
           value={mode} onChange={event => update ('mode', event.target.value)}>
         {['summary', 'details'].map (value => <option key={value} value={value}>
           {message (value).text}</option>)}
-      </select>{actions}
+      </select>
+      <label className="inline-flex items-center gap-1 text-sm">
+	<input type="checkbox" checked={draft.get ('row_numbers') === '1'}
+	    onChange={event => {
+	      update ('row_numbers', event.target.checked ? '1' : '0')
+	      displayRowNumbers (event.target.checked)
+	    }}/>{label ('rowNumbers')}
+      </label>{actions}
     </div>
     <AnimatedCollapse id={id} open={open}>
     <div className="max-h-[35dvh] overflow-y-auto overscroll-contain
diff --git a/frontend/src/components/counts/CountsResults.tsx b/frontend/src/components/counts/CountsResults.tsx
index 25a0334..ca94d72 100644
--- a/frontend/src/components/counts/CountsResults.tsx
+++ b/frontend/src/components/counts/CountsResults.tsx
@@ -1,5 +1,6 @@
 import LocalisedText from '@/components/LocalisedText'
 import PrefetchLink from '@/components/PrefetchLink'
+import CountsRowNumber from '@/components/counts/CountsRowNumber'
 import CountsNestedTable from '@/components/counts/CountsNestedTable'
 import CountsSortHeader from '@/components/counts/CountsSortHeader'
 import CountsResizeHandle from '@/components/counts/CountsResizeHandle'
@@ -7,7 +8,8 @@ import CountsSelectableTable from '@/components/counts/CountsSelectableTable'
 import PostThumbnailPreview from '@/components/posts/PostThumbnailPreview'
 import { changeCountSort, countColumns, countsRequestParams, fieldsForCounts,
 	 readCountSort, selectedCountColumns, writeCountSort } from '@/lib/counts'
-import { countsCellCopy, countsCellText, countsImageURL, countsNestedRows } from '@/lib/countsDisplay'
+import { countsCellCopy, countsCellText, countsImageURL, countsNestedRows }
+    from '@/lib/countsDisplay'
 import useDialogue from '@/lib/dialogues/useDialogue'
 import { useLocale } from '@/lib/useLocale'
 import { useCountsDefinition } from '@/lib/countsDefinitions'
@@ -30,6 +32,8 @@ const CountsResults = (
   const locale = useLocale ()
   const dialogue = useDialogue ()
   const columns = selectedCountColumns (resource, params, definition)
+  const rowNumbers = params.get ('row_numbers') === '1'
+  const tableColumns = rowNumbers ? ['row_number', ...columns] : columns
   const fields = fieldsForCounts (resource, definition)
   const sorts = readCountSort (params.get ('sort') ?? 'created_at:desc')
   const sort = (key: string, additive: boolean) =>
@@ -94,14 +98,15 @@ const CountsResults = (
   }
   return (
       <div className="min-h-0 flex-1 overflow-auto" data-counts-results aria-busy={pending}>
-	{columns.length === 0 ? <p>{label ('nested.noColumns')}</p> : (
+	{tableColumns.length === 0 ? <p>{label ('nested.noColumns')}</p> : (
 	    <CountsSelectableTable family={resource}
-		columns={columns}
-		identity={`${resource}:${countsRequestParams (params)}:${columns.join (',')}:${
+		columns={tableColumns}
+		identity={`${resource}:${countsRequestParams (params)}:${tableColumns.join (',')}:${
 		    (data.versions ?? []).map (row => row.id)}`}
 		className="text-left text-sm">
 	      <thead className="sticky top-0 z-20 bg-background text-foreground
 		  dark:bg-background dark:text-foreground"><tr>
+		{rowNumbers && <CountsRowNumber/>}
 		{columns.map (column => column === 'thumbnail'
 		    ? <th key={column} data-counts-heading={message (countColumns[column]).text}
 			className="relative px-2 py-1">
@@ -114,8 +119,10 @@ const CountsResults = (
 			    field => field.key === column)?.children != null}/>)}
 	      </tr></thead>
 	      <tbody>
-		{(data.versions ?? []).map (row => (
+		{(data.versions ?? []).map ((row, index) => (
 		    <tr key={row.id} className="border-b dark:border-slate-700">
+		      {rowNumbers && <CountsRowNumber
+			  value={(data.page - 1) * data.limit + index + 1}/>}
 		      {columns.map (column => (
 			  <td key={column}
 			      className="overflow-hidden break-words border-b px-2 py-1
diff --git a/frontend/src/components/counts/CountsRowNumber.tsx b/frontend/src/components/counts/CountsRowNumber.tsx
new file mode 100644
index 0000000..11f77a0
--- /dev/null
+++ b/frontend/src/components/counts/CountsRowNumber.tsx
@@ -0,0 +1,17 @@
+import CountsResizeHandle from '@/components/counts/CountsResizeHandle'
+import { useUITranslation } from '@/lib/useUITranslation'
+
+
+const CountsRowNumber = ({ value }: { value?: number }) => {
+  const { label, message } = useUITranslation ('counts')
+  if (value != null) return <td data-counts-copy={String (value)}
+      className="border-b px-2 py-1 text-right align-top tabular-nums dark:border-slate-700">
+    {value}</td>
+  return <th data-counts-heading={message ('rowNumbers').text} className="relative px-2 py-1">
+    {label ('rowNumbers')}
+    <CountsResizeHandle field="row_number" label={message ('rowNumbers')}/>
+  </th>
+}
+
+
+export default CountsRowNumber
diff --git a/frontend/src/components/counts/CountsSummaryResults.tsx b/frontend/src/components/counts/CountsSummaryResults.tsx
index 30e8b1c..cc1c6b7 100644
--- a/frontend/src/components/counts/CountsSummaryResults.tsx
+++ b/frontend/src/components/counts/CountsSummaryResults.tsx
@@ -1,4 +1,5 @@
 import PrefetchLink from '@/components/PrefetchLink'
+import CountsRowNumber from '@/components/counts/CountsRowNumber'
 import CountsSelectableTable from '@/components/counts/CountsSelectableTable'
 import CountsSortHeader from '@/components/counts/CountsSortHeader'
 import { changeCountSort, countsRequestParams, readCountSort, writeCountSort } from '@/lib/counts'
@@ -15,11 +16,13 @@ const CountsSummaryResults = (
         pending: boolean; update: (key: string, value: string) => void },
 ) => {
   const { label, message } = useUITranslation ('counts')
+  const rowNumbers = params.get ('row_numbers') === '1'
   const rows = data.rows ?? []
   const cols = data.cols ?? []
   const axes = [...rows, ...cols]
   const cells = data.cells ?? []
-  const rowKeys = [...new Set (cells.map (cell => JSON.stringify (cell.values.slice (0, rows.length))))]
+  const rowKeys = [...new Set (cells.map (cell => JSON.stringify (
+      cell.values.slice (0, rows.length))))]
   const columnKeys = data.columnValues?.map (values => JSON.stringify (values))
       ?? [...new Set (cells.map (cell => JSON.stringify (cell.values.slice (rows.length))))]
   if (cols.length === 0 && columnKeys.length === 0) columnKeys.push ('[]')
@@ -46,12 +49,13 @@ const CountsSummaryResults = (
     next.delete ('page')
     return `/counts/${resource}?${next}`
   }
-  const keys = [...rows.map ((_, index) => `a${index}`),
+  const keys = [...(rowNumbers ? ['row_number'] : []), ...rows.map ((_, index) => `a${index}`),
       ...columnKeys.map ((_, index) => `cell${index}`)]
   return <div className="min-h-0 flex-1 overflow-auto" data-counts-results aria-busy={pending}>
     <CountsSelectableTable family={`pivot_${resource}`} columns={keys}
         identity={`${countsRequestParams (params)}:${keys}`} className="text-left text-sm">
       <thead className="sticky top-0 z-20"><tr>
+	{rowNumbers && <CountsRowNumber/>}
         {rows.map ((axis, index) => <CountsSortHeader key={axis.field} field={`a${index}`}
             label={message (countsFieldLabel (axis.field))} sorts={sorts}
             change={(key, additive) => update ('sort', writeCountSort (
@@ -65,16 +69,18 @@ const CountsSummaryResults = (
               ...new TextEncoder ().encode (key)].map (byte =>
                   byte.toString (16).padStart (2, '0')).join ('')}`
           return <CountsSortHeader key={key} field={`cell${index}`}
-              label={{ text: name || message ('count').text, language: message ('count').language }}
+	      label={{ text: name || message ('count').text,
+		  language: message ('count').language }}
               sorts={sorts.map (sort => sort.key === sortKey
                   ? { ...sort, key: `cell${index}` } : sort)}
               change={(_, additive) => update ('sort', writeCountSort (
                   changeCountSort (sorts, sortKey, additive)))}/>
         })}
       </tr></thead>
-      <tbody>{rowKeys.map (rowKey => {
+      <tbody>{rowKeys.map ((rowKey, rowIndex) => {
         const rowValues = JSON.parse (rowKey) as (string | number | null)[]
         return <tr key={rowKey}>
+	  {rowNumbers && <CountsRowNumber value={(data.page - 1) * data.limit + rowIndex + 1}/>}
           {rowValues.map ((value, index) => <td key={index}
               className="overflow-hidden break-words border px-2 py-1 dark:border-slate-700"
               data-counts-copy={display (value, rows[index], index)}>
@@ -82,7 +88,8 @@ const CountsSummaryResults = (
           {columnKeys.map (columnKey => {
             const columnValues = JSON.parse (columnKey) as (string | number | null)[]
             const values = [...rowValues, ...columnValues]
-            const cell = cells.find (cell => JSON.stringify (cell.values) === JSON.stringify (values))
+	    const cell = cells.find (cell => JSON.stringify (
+		cell.values) === JSON.stringify (values))
             return <td key={columnKey} data-counts-copy={String (cell?.count ?? 0)}
                 className="border px-2 py-1 dark:border-slate-700">
               <PrefetchLink to={drill (values)}>{cell?.count ?? 0}</PrefetchLink>
diff --git a/frontend/src/lib/counts.ts b/frontend/src/lib/counts.ts
index 68b50d9..562c294 100644
--- a/frontend/src/lib/counts.ts
+++ b/frontend/src/lib/counts.ts
@@ -304,11 +304,18 @@ export const isCountsState = (params: URLSearchParams): boolean =>
     params.get ('definition') !== 'history'
 
 
+export const countsUseLatest = (params: URLSearchParams): boolean =>
+    params.get ('current') === '1'
+    || (params.get ('current') !== '0' && !params.get ('at'))
+
+
 export const countsRequestParams = (params: URLSearchParams): URLSearchParams => {
   const result = new URLSearchParams (params)
   for (const key of ['columns', 'summary_columns', 'children', 'child_sort',
-                    'nested_json', 'order', 'basis', 'axis', 'latest', 'grain'])
+		    'nested_json', 'order', 'basis', 'axis', 'latest', 'grain',
+		    'current', 'row_numbers'])
     result.delete (key)
+  if (isCountsState (params) && countsUseLatest (params)) result.delete ('at')
   return result
 }
 
@@ -331,10 +338,16 @@ export const exportCounts = (
     headers: string[],
     labels: Record<string, string>,
     onError?: () => void,
-): Promise<void> => apiDownload ('/counts/export', {
-    ...Object.fromEntries (params), resource, format,
-    columns: columns.join (','), headers: JSON.stringify (headers),
-    labels: JSON.stringify (labels) }, locale, onError)
+): Promise<void> => {
+  const payload = new URLSearchParams (params)
+  payload.delete ('current')
+  payload.delete ('row_numbers')
+  if (isCountsState (params) && countsUseLatest (params)) payload.delete ('at')
+  return apiDownload ('/counts/export', {
+      ...Object.fromEntries (payload), resource, format,
+      columns: columns.join (','), headers: JSON.stringify (headers),
+      labels: JSON.stringify (labels) }, locale, onError)
+}
 
 
 
diff --git a/frontend/src/lib/countsTableLayout.ts b/frontend/src/lib/countsTableLayout.ts
index 50caf73..f21cb59 100644
--- a/frontend/src/lib/countsTableLayout.ts
+++ b/frontend/src/lib/countsTableLayout.ts
@@ -4,7 +4,7 @@ export const MIN_COUNT_WIDTH = 64
 export const MAX_COUNT_WIDTH = 2000
 
 export const defaultCountWidths: Record<string, number> = {
-    thumbnail: 88, resource_id: 88, version_no: 88, is_latest: 104,
+    row_number: 72, thumbnail: 88, resource_id: 88, version_no: 88, is_latest: 104,
     title: 300, url: 300, thumbnail_base: 300, tags: 560, parents: 180,
     video_ms: 120, original_created_at: 260, original_created_from: 240,
     original_created_before: 240, name: 240, names: 480, category: 180,
diff --git a/frontend/src/lib/useClientMotion.ts b/frontend/src/lib/useClientMotion.ts
index 922c2ad..83f96fd 100644
--- a/frontend/src/lib/useClientMotion.ts
+++ b/frontend/src/lib/useClientMotion.ts
@@ -1,4 +1,5 @@
 import { useReducedMotion } from 'framer-motion'
+import { useEffect, useState } from 'react'
 
 import { clientAnimationTransition, clientMotionTokens } from '@/lib/clientAnimation'
 import { useClientBehaviourSettings } from '@/lib/useClientBehaviourSettings'
@@ -7,7 +8,9 @@ import { useClientBehaviourSettings } from '@/lib/useClientBehaviourSettings'
 export const useClientMotion = () => {
   const settings = useClientBehaviourSettings ()
   const osReduced = useReducedMotion ()
-  const mode = osReduced ? 'reduced' : settings.animation ?? 'normal'
+  const [hydrated, setHydrated] = useState (false)
+  useEffect (() => setHydrated (true), [])
+  const mode = hydrated ? (osReduced ? 'reduced' : settings.animation ?? 'normal') : 'normal'
   const reduced = mode !== 'normal'
   const duration = (kind: keyof typeof clientMotionTokens.durationMS) =>
       reduced ? 0 : clientMotionTokens.durationMS[kind]
diff --git a/frontend/src/locales/ja/counts.json b/frontend/src/locales/ja/counts.json
index a835f6c..2e32ae3 100644
--- a/frontend/src/locales/ja/counts.json
+++ b/frontend/src/locales/ja/counts.json
@@ -217,5 +217,6 @@
     "children": "子項目",
     "profile": "出力設定",
     "path": "出力パス"
-  }
+  },
+  "rowNumbers": "行番号"
 }
diff --git a/frontend/src/pages/CountsResourcePage.tsx b/frontend/src/pages/CountsResourcePage.tsx
index abb050f..4c0a927 100644
--- a/frontend/src/pages/CountsResourcePage.tsx
+++ b/frontend/src/pages/CountsResourcePage.tsx
@@ -39,6 +39,7 @@ const CountsResourceContent = ({ resource }: { resource: CountsResource }) => {
   const controlParams = new URLSearchParams (params)
   controlParams.delete ('nested_json')
   controlParams.delete ('order')
+  controlParams.delete ('row_numbers')
   const request = countsRequestParams (params)
   const [open, setOpen] = useState (false)
   const [sidebarOpen, setSidebarOpen] = useState (false)
@@ -163,7 +164,7 @@ const CountsResourceContent = ({ resource }: { resource: CountsResource }) => {
                   <ul className="ml-3">
                     {['latest', 'history'].map (definition => {
                       const next = new URLSearchParams ({ definition, mode })
-		      for (const key of ['timezone', 'at'])
+		      for (const key of ['timezone', 'at', 'current'])
                         if (params.get (key)) next.set (key, params.get (key)!)
                       const active = target === resource
                           && params.get ('definition') === definition
@@ -187,6 +188,7 @@ const CountsResourceContent = ({ resource }: { resource: CountsResource }) => {
 		  open={open} setOpen={setOpen}
 		  reorder={value => update ('order', value)}
 		  displayJSON={enabled => update ('nested_json', enabled ? '1' : '0')}
+		  displayRowNumbers={enabled => update ('row_numbers', enabled ? '1' : '0')}
 		  execute={next => {
 		    if (next.toString () === canonical) void refetch ()
 		    else setParams (next)