Subtitle Edit

the subtitle editor :)

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Batch Convert

Convert multiple subtitle files between formats and apply various transformations.

• Menu: Tools → Batch convert…

How to Use

1. Open Tools → Batch convert…
2. Add subtitle files (drag and drop, or use the Add button). The folder button adds every subtitle file in a folder — drag and drop works with folders too. Turn on Include subfolders when adding a folder in the settings (gear button) to scan the whole tree; a scan of a large tree or a network share can be cancelled while it runs.
3. Select the output format
4. Optionally add conversion functions (fixes, adjustments)
5. Choose an output folder
6. Click Convert

Available Functions

You can chain multiple conversion functions:

• Fix common errors
• Remove text for hearing impaired
• Multiple replace
• Change casing
• Change formatting (add/remove)
• Offset time codes
• Adjust duration
• Change speed/frame rate
• Beautify time codes — align cues to frames and apply the Beautify time codes profile rules; frame rate and shot changes are read from a video file with the same name as the subtitle file, if one is found
• Snap all times to frames — round every start and end time to the nearest frame, using the frame rate of a video file with the same name as the subtitle file or a fixed frame rate you choose
• Convert colors to dialog — turn a color change inside a cue into a dash-prefixed dialog, optionally removing the color tags, adding new lines and re-breaking the lines
• Bridge gaps
• Apply minimum gap
• Apply duration limits
• Merge lines with same text
• Merge lines with same time codes
• Merge short lines
• Split/break long lines
• Unbreak lines — join a cue’s lines into one, optionally only for short ones
• Auto-balance lines
• Fix right-to-left
• Sort by
• Change resolution — the ASSA resolution resampler applied to every file
• Change style — swap one ASSA style for another, or import styles from a file, optionally trimming unused ones
• Embed fonts — embed the fonts an ASSA file uses as attachments, optionally trimmed to the characters actually used
• Adjust image brightness/alpha/color — for image-based subtitles
• Auto translate
• Delete lines

Auto-translate in Batch Convert

Batch Convert can machine-translate files as part of the conversion. Supported engines:

• Ollama
• Ollama advanced (local LLM) — the batch/context engine described in Advanced local engines, talking to Ollama’s OpenAI-compatible endpoint
• LibreTranslate
• LM Studio
• llama.cpp — fully managed: Batch Convert reuses an already-running local llama-server, or downloads llama.cpp plus a curated translation model (e.g. TranslateGemma) and starts the server for you. Point it at your own server via the remote-server option in Auto-translate settings.
• llama.cpp advanced (local LLM) — the batch/context engine described in Advanced local engines; it gets the context size configured there
• NLLB (nllb-serve and nllb-api)
• DeepL (API key required)
• CrispASR MADLAD

The same feature is available headlessly in seconv via --translate-to — see the command line documentation.

OCR in Batch Convert

Batch Convert can OCR image-based subtitle files while converting them to text-based formats.

Supported OCR engines in Batch Convert:

• nOcr
• BinaryOcr
• Tesseract
• Ollama
• llama.cpp (curated OCR vision models, best-first — GLM-OCR, PaddleOCR-VL, HunyuanOCR 1.5, LightOnOCR; a local llama-server is started automatically)
• CrispEmbed (local, multiple model backends — see OCR)
• PaddleOCR (Windows and Linux only)

Subtitle Edit 5 can auto-detect language and pixels-are-space settings for nOcr/BinaryOcr in many batch workflows. This reduces the amount of manual setup needed when converting many image-based subtitle files with similar fonts.

Speech to Text in Batch Mode

Speech-to-text batch mode can transcribe multiple media files and save the results next to the source files. See Speech to Text for engine setup and model details.

Settings

• Output format — Choose from 380+ subtitle formats
• Output folder — Where converted files are saved
• Overwrite existing — Whether to overwrite files
• Encoding — Text encoding for output files

For headless batch conversion, see Command Line (seconv).