CaptionKit
Free · No signup · Browser-first

Subtitle tools that stay out of your way.

Convert subtitle formats, fix timing and prepare voiceover scripts in seconds. Local tools run entirely in your browser.

Explore free tools

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00:00:01,000 → 00:00:03,500

Create without limits.

WEBVTT

00:00:01.000 → 00:00:03.500

Your file never leaves this device for local tools.

Everything you need for cleaner captions

Focused tools for common subtitle and voiceover tasks—without accounts, uploads or complicated workflows.

Runs locally

Subtitle Checker & SRT Validator

Check SRT and VTT files for timing, overlap, numbering, duration and line-length errors.Open tool
Runs locally

SRT ↔ VTT Converter

Convert SubRip subtitle files to standards-compliant WebVTT in your browser. Convert WebVTT captions into clean, numbered SRT subtitles.
SRT → VTTVTT → SRT
Runs locally

SRT to TXT Converter

Extract dialogue from SRT subtitles for scripts, notes or reuse.Open tool
Runs locally

Subtitle Time Shifter

Move every SRT or VTT cue forward or backward to fix sync.Open tool
Runs locally

Subtitle Cleaner

Clean SRT and VTT formatting, tags, numbering, spaces, BOM and line endings locally.Open tool
Runs locally

Subtitle Delay Calculator

Calculate the exact time offset between a video moment and its subtitle cue.Open tool
Runs locally

Subtitle FPS Converter

Convert SRT or VTT timing between 23.976, 24, 25, 29.97 and 30 FPS.Open tool
Runs locally

SRT ↔ CSV Converter

Convert SRT subtitles to a UTF-8 CSV table for Excel or Google Sheets. Turn subtitle CSV rows into a clean, numbered SRT file in your browser.
SRT → CSVCSV → SRT
Runs locally

Subtitle Reading Speed Calculator

Calculate characters per second (CPS) for every SRT or VTT cue.Open tool
Runs locally

YouTube Subtitle Formatter

Clean spacing, optimize line breaks and check reading speed for YouTube captions.Open tool
Runs locally

TTS Script Splitter

Split long multilingual scripts into natural, size-limited chunks.Open tool

Privacy is the default, not an option

Conversion, extraction, timing, formatting and text splitting happen on your device. Files are never uploaded or stored.