FastTools

Subtitles

Convert, sync, and clean subtitle files instantly in your browser. SRT, WebVTT, and ASS formats supported. No signup, no server uploads.

10 free tools

All Subtitles Tools

Free Subtitle & Caption Tools

Subtitles and closed captions are essential for accessibility, SEO, and reaching global audiences. Whether you're a video editor, translator, content creator, or accessibility specialist, these free browser-based tools handle every common subtitle task without sending your files to any server.

SRT and WebVTT Format Conversion

The two most common subtitle formats — SubRip (SRT) and WebVTT (VTT) — use nearly identical structures but differ in timestamp format and header requirements. SRT uses commas for milliseconds (00:01:23,456) while VTT uses periods (00:01:23.456). HTML5 video requires WebVTT, while most video editing software exports SRT. Our converters handle both directions instantly.

Subtitle Timing and Sync Tools

Out-of-sync subtitles are the most common subtitle problem. If your subtitles run consistently early or late, the time shifter applies a fixed offset to every cue. If they start in sync but drift over time — common with ripped media — the partial subtitle shifter applies linear interpolation between two sync points, correcting progressive drift without manual cue-by-cue editing.

Subtitle Cleaning and Formatting

Subtitle files pulled from streaming services or generated by automated transcription often contain formatting artifacts: duplicate line breaks, hearing-impaired annotations in brackets, trailing whitespace, or inconsistent encoding. The SRT cleaner strips these artifacts and re-sequences cue numbers automatically. The encoding converter handles the common Windows-1252 to UTF-8 migration that causes accented characters to display as garbled symbols.

Frequently Asked Questions

Do these subtitle tools upload my files anywhere?

No. All processing happens entirely in your browser using JavaScript. Your subtitle files never leave your device and are not sent to any server.

What subtitle formats do these tools support?

The tools support SRT (SubRip), WebVTT (.vtt), and ASS/SSA (Advanced SubStation Alpha). SRT and VTT are covered by most tools; ASS format is supported by the SRT to ASS converter.

Why are my subtitles showing garbled characters after conversion?

This usually means the original file was encoded in Windows-1252 (common for older SRT files) rather than UTF-8. Use the Subtitle Encoding Converter to fix this — it detects and converts the encoding while preserving all text content.

How do I fix subtitles that start in sync but drift out later?

This is progressive drift, usually caused by a frame rate mismatch. Use the Partial Subtitle Shifter — enter two sync points (where subtitles are correct and where they are wrong) and the tool linearly interpolates the correction across all cues between them.

Can I use these tools on my phone?

Yes, all tools are mobile-responsive. However, file upload/download works best on desktop browsers. On mobile, you can paste subtitle text directly into the text input fields.

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