SUBTITLE QUALITY / CPS CHECKER

CPS checker.

Paste SRT or VTT subtitles, or choose a file. Check every cue's reading speed, line length, duration and line count before you use it.

All checks run in your browser. Your subtitle text and files are never uploaded to a server.

Optional analytics helps us count page visits. It never receives your subtitle files. Allow Google Analytics?

01 · Choose file

No file selected

UTF-8 SRT or WebVTT, up to 5 MB. Loading a file places its text in the box so you can inspect or change it.

02 · Paste or review text

Subtitle source

Paste subtitles or choose a file to begin.

Flags: more than 17 characters per second · any line longer than 42 characters · cue shorter than 0.83 seconds · more than two visible lines. A cue can have several flags.

Results for this file

Format—

Cues checked—

Cues with any flag—

Average CPS—

Highest CPS—

CPS > 17: —Line > 42: —Duration < 0.83 s: —More than 2 lines: —Skipped blocks: —

Cue	Timing	Text	Duration	Chars	CPS	Longest line	Lines	Flags

How CPS is counted

For each cue, CPS = visible character count ÷ cue duration in seconds. Spaces and punctuation inside a line count; line breaks and subtitle markup do not. Each displayed character is counted as one grapheme where the browser supports it. The line limit uses the longest visible line, not the whole cue.

Read the flags together

“Cues with any flag” counts each cue once, even if it exceeds several limits. Average CPS is the arithmetic mean of all readable cue CPS values. Empty, mistimed or unrecognized blocks are skipped and counted separately. These thresholds are checks, not proof that subtitles will be comfortable for every viewer.

Need to change a format first? Use VTT to SRT, SRT to VTT, Text to SRT, SRT to TXT, VTT to TXT, the subtitle converter, ASS to SRT, or SUP to SRT.