Subtitle readability checker

Find overlapping captions, invalid times, long lines and fast reading speeds.

Up to 2 MB of caption text. Review each caption against the recording.

Runs on your device. Your captions are not uploaded.

Your result

Open or paste captions to begin.

These checks flag captions to look at again. They do not compare the words with your audio.

Studio keeps captions short enough to read and styles them for vertical clips.

00:20How it works

Open or paste your captionsChoose an SRT or WebVTT file, or paste the caption text.
Press Check captionsPick the download format and any timing first.
Check and downloadSave the file as SRT, WebVTT or plain text, then play it with your video.

00:30Good to know

Which caption files work?

SRT and WebVTT files, up to 2 MB. You can also paste the caption text straight in.

Are my captions uploaded?

Caption editing and checks run on your device. Translation sends caption text to our AI service when you choose Translate.

Does it check the words against my audio?

It works on the caption file only. Play the result with your video before you publish.

Is it free?

Yes, with no account. Download as SRT, WebVTT or plain text as often as you like.

Convert SRT or WebVTT captions into SRT, VTT or plain text on your device.

Edit individual caption text and timestamps, then export a subtitle file.

Move every caption forwards or backwards by an exact offset.

Retiming captions from one frame rate to another keeps their relative spacing.

Distinguish a constant offset from drift and individual cue errors before changing timing.

Use reading-speed and line-length flags to find cues that need a human review.

An invented caption word can land on a card as if you said it.

Upload the raw recording. Studio cuts the ums, retakes and long pauses, adds captions and makes short clips. 30 free minutes, no card.