Batch Subtitle Converter
Convert dozens of supported subtitle files to one target format — SRT, VTT, ASS, LRC, or TXT — all at once.
Drag & drop your subtitle file here
Drag and drop subtitle files here or click to browse
Why Use the Batch Converter?
Engineered for video editors and localization teams. Helps enforce common subtitle timing rules and formatting.
Batch Subtitle Converter Live Execution Demo
In-Memory Processing
File parsing, mutations, and time shifts for standard tools run in browser memory without sending subtitle files to our servers.
Millisecond Precision
Millisecond-accurate timecode parsing and arithmetic prevent synchronization drift across desktop and web players.
Fault-Tolerant Engine
Automatic multi-encoding detection and syntax sanitization gracefully handle malformed cues and unexpected linebreaks.
Who Needs Batch Subtitle Conversion?
Real-world scenarios across video post-production, course transcription, and global localization.
Video Editors & Post-Production
Convert an entire episode or season worth of subtitles from one format to another without opening each file separately.
Streaming Platforms & OTT
Deliver subtitle tracks in the exact format your platform requires — convert a library of VTT files to SRT or ASS in one pass.
Translators & Localization Teams
Standardize subtitle formats before sending them to translation tools or CAT software that only accept specific formats.
Content Creators & YouTubers
Batch-convert downloaded captions to TXT for transcripts, or to LRC for karaoke-style lyric syncing.
Archive & Library Digitization
Migrate large collections of legacy subtitle files to modern web-friendly formats like VTT.
Educators & Course Platforms
Prepare accessible subtitle files for video lessons across multiple courses in a single batch run.
How It Works
Streamlined end-to-end processing pipeline engineered for speed and precision.
Upload & Import
Drag and drop subtitle files into the upload area, or click to browse. Supported inputs can be mixed in the same batch.
Format Analysis
Each file's format is detected automatically and shown as a tag next to the filename.
Configuration
Choose your target output format from the buttons above the file list (SRT, VTT, ASS, LRC, or TXT).
Processing
The selected target format applies to every file in the batch.
Click Convert All Files
Every file is converted to the selected format in seconds.
Delivery
Download individual files or grab the whole batch as a ZIP archive.
Why Choose AllSubConverter?
Client-Side Privacy
Standard tools run in your browser so standard files are not uploaded to our servers.
Fast Local Parsing
Optimized processing engine parses and converts files directly in your browser.
Generous Batches
Up to 50 MB per file, 200 files or 1 GB total per batch.
Universal Compatibility
Runs in modern browsers across Windows, macOS, Linux, iOS, and Android.
More Subtitle Tools
Frequently Asked Questions
A batch can contain up to 200 files, 1 GB of files in total, and each file can be up to 50 MB. Processing happens in your browser, so available device memory can still affect very large files.
No. The batch converter applies a single output format to every file in the list. Choose SRT, VTT, ASS, LRC, or TXT before clicking Convert All. If you need multiple output formats, run separate batches.
When you add a file, the converter checks its supported extension. If needed, it also inspects the content for markers such as the WEBVTT header or an ASS [Script Info] block.
It accepts the supported subtitle inputs, including SRT, VTT, ASS, SSA, LRC, SBV, TTML, SCC, STL, SMI, TXT, and YouTube JSON3. Input formats are auto-detected, and each file must have a supported source-to-target conversion route.
No. All conversion happens entirely in your browser using JavaScript. Your files never leave your device, which makes the batch converter safe to use even for confidential or unreleased content.
If a file has an unknown extension and no recognizable content markers, it is marked as 'Skipped' and excluded from conversion. You can still convert the rest of the batch and fix the skipped files separately.
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