Caption Fit Lab

Characters per second for Shorts: a readable cue length

If a line flashes too fast, viewers miss it. Check characters per second before you burn captions in.

12 November 2026

Answer: Paste or load your SRT in Speed check. Flag cues over your CPS limit, then fix timing or split the line before export.

Tool: Subtitle speed checker — free, runs in this browser.

Words per minute and characters per second measure the same problem from different angles: too much text for the time the cue is on screen.

Short-form video rewards short lines. A caption that works on a laptop transcript often fails on a phone when the safe zone already eats the bottom third.

Fix the worst offenders first — the spikes — then re-check the file. Export a new SRT only after the speed list is clean enough for your audience.

Open Subtitle speed checker

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