WAVESPEED AI SUBTITLE EDITOR Files stay on your device

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Subtitle EditorEdit, time and convert subtitles in your browser.

Open SRT, VTT, ASS, SSA, SBV, TTML, SUB or LRC files with your video and edit them on a waveform timeline, with the subtitles shown over the picture as you work.
Fix timing and drift, check reading speed and line length, clean up hearing-impaired notes, then save in any format, convert a whole folder, or burn them into the video.

Waveform timeline10 formatsTiming & sync tools

No sign-up No upload No watermark

Drop subtitles and a video

Open a subtitle file, a video or audio file, or both at once. Several subtitle files open the batch converter.

SRTVTTASSSSASBVTTMLDFXPSUBLRCTXT

Old files in Windows code pages, GB18030, Shift_JIS or EUC-KR are read correctly.

THREE SIMPLE STEPS

How to edit subtitles

Open your files

Drop a subtitle file and its video or audio. With only a video, start from scratch and type the subtitles as it plays.

Edit and time

Change text in the list, drag cues on the waveform, set start and end at the playhead with [ and ], and shift or sync the whole file.

Check and save

Fix what breaks the reading-speed and line-length rules, then download in the format you need or burn the subtitles into the video.

GOOD SUBTITLES

Rules of thumb for readable subtitles

Reading speed

Around 17 characters per second suits most adult viewers, about 13 for children. Faster cues get read only halfway: shorten the text or lengthen the cue.

Line length

Keep to about 42 characters per line and two lines per cue, breaking lines at natural pauses. Chinese, Japanese and Korean characters count double here, since they are about twice as wide.

Timing

Show each cue for at least 5/6 of a second and no more than 7 seconds, and leave two frames (about 83 ms) between cues so the eye sees the change.

WaveSpeed AI

Make the video, then subtitle it.

Create clips from a prompt or an image with WaveSpeed AI, then edit their subtitles here for free.

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Pay as you go

$1 in free credits for eligible new accounts. No card needed. Generators have separate account and credit requirements. The subtitle editor is free.

Subtitle Editor FAQ

Is this subtitle editor free?

Yes. Edit, convert, batch convert and burn in as many files as you like, with no account and no watermark.

Are my files uploaded?

No. Subtitles, video and audio are opened and processed in your browser. The project is saved in this browser so you can continue later; nothing is sent to a server.

Which formats can it open and save?

SubRip (.srt), WebVTT (.vtt), Advanced SubStation (.ass), SubStation Alpha (.ssa), YouTube SubViewer (.sbv), TTML and DFXP (.ttml, .dfxp, .xml), MicroDVD (.sub, by frame number; SubViewer .sub files open too), LRC lyrics (.lrc) and plain text. Every one can be saved in every other.

Are ASS styles and effects kept?

Saved as ASS again, the file keeps its script info, styles, speakers, layers, margins, effects and override tags such as positions and fades. Saved as SRT, italic, bold, underline, colour and top position stay; other formats keep what they can express.

My subtitles show strange characters. What can I do?

Old subtitle files are often saved in a Windows code page or a Chinese, Japanese or Korean encoding. The editor detects the encoding, and if the guess is wrong you can pick another one next to the file name: the file is read again. Everything is saved as UTF-8.

How do I fix subtitles that drift out of sync?

Open Timing and use Sync by two points: enter the right start time for a cue near the beginning and one near the end (or play the video and take the playhead). Cues in between are stretched linearly. For a constant delay use Shift; for a video converted between 23.976 and 25 fps use Change frame rate.

Can I subtitle a video from scratch?

Yes. Open only the video, play it and press Alt+N to add a cue, [ and ] to set its start and end at the playhead, then type. You can also drag across the waveform to create a cue. For automatic subtitles from speech, use the free Subtitle Generator.

How big can my files be?

Subtitle files with thousands of cues are fine. Videos are not loaded into memory to play; the waveform is read in the background. Burning subtitles into a long video can take a while, as every frame is encoded again in your browser.

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