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.

2 tools

Convert Drop-Frame Timecode to Non-Drop-Frame

Re-label every subtitle timecode from 29.97 drop-frame back to 30 fps non-drop — an hour in, 01:00:03,600 becomes 01:00:00,000.

Convert Non-Drop-Frame Timecode to Drop-Frame

Re-label every subtitle timecode from 30 fps non-drop to 29.97 drop-frame — an hour in, 01:00:00,000 becomes 01:00:03,600.

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.

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.

Detect structural subtitle defects: overlaps, gaps, empty cues, non-monotonic timing and unusual cue durations — one page per problem or all at once.

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.

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.

Extract subtitle tracks from video, transcribe speech with Whisper, OCR PGS and VobSub bitmaps, voice subtitles and resync audio — all inside your browser.