Accessibility compliance
Check subtitles against reading speed, line length and display-duration thresholds from EN 301 549, WCAG 1.2.2, FCC, Ofcom, Netflix and BBC rules.
9 tools · Pages in this category cite the clauses they check against.
Check Captions Against EN 301 549 and WCAG 1.2.2
Run the whole check against the European accessibility standard, which adopts WCAG 2.2 SC 1.2.2 as a requirement — the same file reads as an error here and a warning there.
Check Subtitle Speaker Identification
List every cue where two people speak but neither is named, checked against FCC 47 CFR §79.1 and WCAG 2.2 SC 1.2.2, and download the report.
Check Subtitle Line Length
Measure every subtitle line against Netflix's 42-character and the BBC's 37-character limits, line by line, and download the report. The file is never uploaded.
Check Subtitle Maximum Duration
List every cue still on screen after Netflix's seven seconds, with the duration it measured, the limit it was compared against and the sentence that limit was read from.
Check Subtitle Minimum Duration
List every cue on screen for less than Netflix's five sixths of a second (834 ms), with the measured duration and the sentence the limit came from.
Check Subtitle Reading Speed
Measure how fast every cue has to be read, checked against Ofcom's 180 words per minute or Netflix's 20 characters per second, and download the report.
Check Subtitles Against the FCC Caption Rules
Run the whole check against 47 CFR §79.1 — four of the five checks come back with no figure to compare against, because that rule states none, and the report says so.
Check Subtitles Against the Netflix Timed Text Style Guide
Run the whole check against Netflix's numbers at once — 20 characters per second, 42 characters a line, 834 ms to 7 seconds a cue — and name the rule it cannot check yet.
Check Subtitles Against Ofcom Guidance
Run the whole check against Ofcom's published guidance, whose only figure is a reading speed of 180 words per minute — the report shows what the rest of the document leaves open.
Other categories
Format conversion
Move subtitles between SRT, WebVTT, ASS, SSA, SBV, SMI, LRC, MicroDVD, TTML, JSON, plain text and CSV — and see what each conversion drops before it runs.
Timing
Shift, scale, re-frame and re-align subtitle timing: frame-rate conversion, overlap and gap repair, trimming to a range and splitting a file into parts.
Text and styling
Change case, strip tags and SDH descriptions, recolour or reposition lines, merge or split bilingual tracks, find and replace, rewrap lines, fix encoding.
Quality checks
Detect structural subtitle defects: overlaps, gaps, empty cues, non-monotonic timing and unusual cue durations — one page per problem or all at once.
Timecode
Re-label subtitle timecodes between 30 fps non-drop and 29.97 drop-frame, two conventions that drift 3.6 seconds apart every hour, in both directions.
Export and integration
Turn subtitles into an HTML track element, a YouTube chapter list, a plain text transcript or a printable PDF — outputs no subtitle format can carry.
Media input
Extract subtitle tracks from video, transcribe speech with Whisper, OCR PGS and VobSub bitmaps, voice subtitles and resync audio — all inside your browser.