How does the batch size work?

The tool groups cues into fixed batches of 30 and translates each batch in one API call. The batch size is not adjustable in this version.

What if the translation quality is poor?

Try a higher-quality model. Also, ensure the source language is correctly set (or use auto-detect). Very short or heavily colloquial text may need manual review.

Can I translate subtitles to English or another language online?

Yes. The browser parses the file locally and sends cue text directly to your chosen provider with your API key. Choose the source and target language, then export an SRT, VTT, or ASS file with timing preserved.

How do I review or reuse an AI-translated subtitle?

Open the exported file in the [subtitle editor](/subtitle-editor/) to polish terminology and line breaks. To show the original and translation together, align them with the [bilingual merger](/bilingual-merger/). For multiple finished files, continue in the [batch converter](/batch-converter/).

Can I use GPT or another LLM to translate subtitles?

Yes. Bring your own API key for OpenAI or an approved OpenAI-compatible provider, then choose an LLM model available from that provider. Subtitle parsing happens locally, while cue text and your key are sent directly from your browser to the provider. Timing and cue order stay aligned in the exported file.

Does this AI subtitle language converter support ASS files?

Yes. You can convert subtitle language from an ASS input and export SRT, VTT, or ASS. Advanced ASS source styling is normalized during processing, so review the output if your file relies on complex styles.

AI Subtitle Translator

Translate your subtitles into 19 built-in target languages. Bring your own API key for OpenAI or an approved OpenAI-compatible provider.

Drag & drop your subtitle file here

Drag and drop subtitle files here or click to browse

SRT, VTT, ASS, SSA, LRC, SBV, TTML, SCC, STL, SMI, TXT, JSON

AI Assisted · Cue Text Sent to Selected Provider

Core Processing Architecture

Key Features

Engineered for video editors and localization teams. Helps enforce common subtitle timing rules and formatting.

AI-powered translation with natural, context-aware results

Choose from 19 fixed target languages, including English, Chinese, Japanese, Korean, Spanish, French, German, and more

Auto-detect source language or specify it manually

Use OpenAI or an approved OpenAI-compatible endpoint with a built-in or custom model ID

Translates cues in fixed batches of 30

Preserves all timing and subtitle structure - only text is translated

Output as SRT, VTT, or ASS format

Supports SRT, VTT, ASS, SSA, LRC, SBV, TTML, SCC, STL, SMI input formats

Your API key stays in memory for the session and is saved locally only after you choose Remember

Real-time progress tracking showing how many cues have been translated

Live Preview & Execution Pipeline

AI Subtitle Translator Live Execution Demo

speech.en.srt

READYSource

00:01.000Subtitle parsing stays local.

00:04.500AI requests go to your selected provider.

speech.es.srt

READYTranslation

00:01.000El análisis de subtítulos se mantiene local.

00:04.500Las solicitudes de IA van al proveedor seleccionado.

Direct Provider Processing

File loading happens in your browser runtime; subtitle batches are sent directly to your chosen AI provider using your configured API key.

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.

Production Workflows

Common Use Cases

Real-world scenarios across video post-production, course transcription, and global localization.

SCENARIO #1

Foreign Films

Translate subtitles for movies or shows that only have subtitles in a language you don't speak.

SCENARIO #2

Language Learning

Generate bilingual subtitles by translating foreign content into your native language.

SCENARIO #3

Content Localization

Translate your video subtitles for international audiences across multiple languages.

SCENARIO #4

Academic Research

Translate foreign-language documentary or lecture subtitles for research purposes.

SCENARIO #5

Travel Content

Translate travel vlog or guide subtitles to reach a global audience.

SCENARIO #6

Corporate Videos

Translate training or promotional video subtitles for multilingual teams.

SCENARIO #7

AI SRT and VTT Translation

Use AI to translate an SRT, VTT, ASS, LRC, SBV, TTML, SCC, STL, or SMI subtitle while preserving cue numbering and timing.

Execution Pipeline

How It Works

Streamlined end-to-end processing pipeline engineered for speed and precision.

STEP 01

Upload & Import

Select your subtitle file.

PHASE 01

STEP 02

Format Analysis

Choose OpenAI or an approved OpenAI-compatible provider, then enter your API key.

PHASE 02

STEP 03

Configuration

Choose the source language (or use auto-detect) and the target language.

PHASE 03

STEP 04

Processing

Select an AI model based on your quality and cost preferences.

PHASE 04

STEP 05

Click Translate

Parsing is local, and cue text is sent in batches directly to your chosen provider.

PHASE 05

STEP 06

Delivery

Download the translated subtitle file in your chosen format.

PHASE 06

Engine Capabilities

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.

Tool Suite

More Subtitle Tools

Subtitle Format Cleaner

Remove formatting, tags and noise

Subtitle Editor

Edit subtitle content and timings

Subtitle Sync & Timing Calibration

Adjust timing with millisecond precision

Subtitle Merger

Combine multiple subtitle files

Batch Subtitle Converter

Convert multiple files at once

Frequently Asked Questions

Yes. The tool connects with your own API key for OpenAI or an approved OpenAI-compatible provider. The key is kept in memory for the session and sent directly to that provider, never to our servers.

The target-language menu has 19 choices: English, Chinese (Simplified and Traditional), Japanese, Korean, Spanish, French, German, Portuguese, Italian, Russian, Arabic, Hindi, Thai, Vietnamese, Indonesian, Turkish, Dutch, and Polish. Source-language auto-detect is also available.

Yes, but one at a time. After translating, click 'Translate Another' and select a different target language with the same file.

Cost depends on your provider, model, and number of cues. Check the provider's current pricing before translating a large file.

Parsing and output generation happen locally. Translation requests, including cue text and your API key, go directly from your browser to the provider you choose. We never see or store your files or key.

Input: SRT, VTT, ASS, SSA, LRC, SBV, TTML, SCC, STL, SMI. Output: SRT, VTT, or ASS.

Ready to convert your subtitles?