Subtitle Converter

Convert subtitle files between SRT, WebVTT, ASS, SSA, SMI, and SUB formats without uploading them to a server. The converter parses timing cues in your browser, preserves readable text, and helps you prepare captions for video editors, media players, learning platforms, and web video workflows.

Supported Formats

SRT
VTT
ASS
SSA
SMI
SUB

Features

100% Browser-Based

Subtitle parsing and conversion run locally in your browser, so private transcripts, unreleased course captions, client review files, and internal video subtitles do not need to leave your device. This is useful when you only need a format change and do not want a cloud upload step.

Multiple Formats

Convert common caption formats including SRT, WebVTT, ASS, SSA, SMI, and MicroDVD SUB. Use SRT for broad compatibility, WebVTT for HTML5 video, or ASS/SSA when a workflow needs styled subtitles before final export.

Batch Processing

Convert up to 50 subtitle files in one session and download files individually or together as a ZIP archive. Batch mode is helpful when preparing multi-episode courses, translated subtitle packs, or multiple versions of a video for different platforms.

Instant Results

Because the work is handled in the browser, there is no upload queue or remote processing delay. Small caption files usually convert immediately, and larger subtitle sets stay under your control while you review detected format, cue count, duration, and encoding details.

Timing-Friendly Conversion

The converter keeps subtitle start and end times aligned while changing container syntax. It is designed for format conversion rather than automatic translation, transcription, or resync, so the text and timing you provide remain the source of truth.

Practical Format Guidance

Choose SRT when you need maximum player support, WebVTT for websites and browser video, and ASS or SSA when your source includes styling. When converting to simpler formats, advanced styling such as colors, positioning, and karaoke effects may be simplified.

Frequently Asked Questions

What subtitle formats can I convert?

You can convert between common subtitle formats including SRT, WebVTT (.vtt), Advanced SubStation Alpha (.ass), SubStation Alpha (.ssa), SAMI (.smi), and MicroDVD (.sub). SRT is usually the safest output when you need broad compatibility with players, editors, and publishing tools.

Is my data safe?

Yes. The conversion runs in your browser, so subtitle files are not uploaded to a remote server for normal processing. This is especially useful for private video projects, client review captions, internal training material, and unreleased media.

Will I lose formatting when converting to SRT?

SRT is a basic caption format and does not support advanced styling. If your ASS or SSA file includes colors, fonts, positioning, karaoke effects, or complex screen placement, those details may be simplified or removed when the output format cannot represent them.

Is there a file size limit?

Each file can be up to 10MB, and you can convert up to 50 files at once.

Which output format should I choose?

Choose SRT for maximum compatibility, WebVTT for web pages and HTML5 video, and ASS or SSA for workflows that need subtitle styling. If you are uploading to a video platform and are unsure, SRT is usually the most widely accepted option.

Does the converter translate or transcribe subtitles?

No. This tool changes subtitle file formats; it does not translate text, create captions from audio, or automatically fix timing. The converted file uses the text and cue timing from your source subtitle file.

Can I use it for YouTube, Vimeo, or online course captions?

Yes, as long as the target platform accepts the output format you choose. SRT and WebVTT are common choices for video platforms, learning management systems, documentation sites, and embedded web video players.

Why do some captions look different after conversion?

Subtitle formats support different capabilities. When converting from a styled format such as ASS or SSA to a simpler format such as SRT, the cue text and timing can remain, but visual styling, placement, and animation may not have an equivalent representation.