Audiovisual & Video

SRT Subtitle Composer

Turn plain voiceover scripts into timed subtitle blocks for .SRT files without manually entering timecodes. The tool segments your text by punctuation, commas, or conjunctions, calculating duration based on natural reading cadence so viewers can comfortably read captions across TikTok, Reels, or horizontal YouTube videos.

100% Private In-Browser Processing

Your files and data are processed strictly in your device's volatile memory. Zero server uploads, no network traffic, and no data is written to disk.

v3.1.4

Original Script

Time & Limits Configuration

Duration per Subtitle (seconds)

Pause Duration (s)

Alert for character limit per line

Recommended: 35 to 42 characters for Reels and Shorts

Generated Subtitles

No sentences generated yet. Paste your text and click 'Generate SRT Sentences'.

100% Private In-Browser Processing

Your files and data are processed strictly in your device's volatile memory. Zero server uploads, no network traffic, and no data is written to disk.

v3.1.4

Subtitle Studio

Part of Subtitle Studio

In addition to composing captions from scripts, you can translate line-by-line and adjust timing offsets in the full Subtitle Studio.

Looking to translate or sync subtitles?

Open Subtitle Studio

Frequently Asked Questions about SRT Composer

How are timecodes calculated for each sentence?

The algorithm calculates display duration from sentence length and word density: using ergonomic words-per-minute (WPM) benchmarks, it enforces safe minimum durations for quick phrases and sensible caps for longer sentences.

Can I enforce character limits?

Yes, because you can enforce strict character limits per block, preventing text from overflowing phone screens or conflicting with native UI overlays on TikTok, Reels, and YouTube Shorts.