Accessibility editors
Improve readability before publishing captions.
Free Subtitle Length Checker
Check SRT cue line length, duration, and reading speed before you publish captions. Free and private in your browser.
Runs in your browserNothing uploadedFree forever
Checks line length (≤42 chars), max 2 lines, duration 1–7s, and ~21 characters/sec.
Cues
3
Issues found
3
Status
Needs review
Paste SRT or VTT
Cue #1 · 00:00:00,000 → 00:00:00,400
Duration 400ms is under 1000ms.
Hi
Cue #2 · 00:00:01,000 → 00:00:08,000
Line has 150 characters (recommended max 42).
This line is intentionally very long so the subtitle length checker will flag characters per line and reading speed issues for demonstration purposes.
Cue #2 · 00:00:01,000 → 00:00:08,000
Reading speed ~21.4 characters/sec (recommended max 21).
This line is intentionally very long so the subtitle length checker will flag characters per line and reading speed issues for demonstration purposes.
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Files stay on your device
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How to check subtitle length online
Three steps to QA caption cues for length and pace without uploading files.
01
Paste or upload SRT / VTT
Drop caption text you plan to publish or deliver to a client.
02
Run cue length checks
We flag long lines, excess lines per cue, short/long durations, and high characters/sec.
03
Fix the listed cues
Review each issue with timing and text, then edit your file before upload.
Why use this free subtitle length checker
Built for creators who want readable captions without installing heavy subtitle software.
Catch caption cues that are too long
Spot lines over ~42 characters and cues with more than two lines.
Check duration and reading speed
Flag flashes under 1s, long holds over 7s, and fast CPS rates.
SRT line length checker in-browser
QA captions without installing desktop subtitle software.
Private subtitle QA
Files stay on your device — nothing uploaded to Scribia.
Who checks caption cue length
YouTube creators
Reduce viewer drop-off from unreadable on-screen text.
Localization teams
Sanity-check translated SRT files for length blowups.
Ready for the full Scribia workspace?
QA is easier with a solid source transcript. Scribia generates timed transcripts from YouTube and uploads so you can edit, export, and caption with less cleanup.
Frequently asked questions
Answers about privacy, limits, and how this free free subtitle length checker works.
What does a subtitle length checker look for?
Common readability rules: max characters per line, max lines per cue, minimum/maximum on-screen duration, and characters-per-second reading speed.
Why is my caption cue too long?
Viewers struggle when a single line exceeds roughly 42 characters or a cue stacks more than two lines. Split or shorten the dialogue.
Does this replace professional caption standards?
It is a practical free QA helper, not a certified compliance suite. Use it for fast checks before deeper review.
Is my SRT uploaded?
No. Parsing and checks run entirely in your browser.
Need captions from the video source?
This checker reviews existing SRT/VTT. Scribia creates transcripts and summaries from the video itself.
Browser-only processing
No file uploads
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