Frequently Asked Questions (FAQ)

General

What is Subtitle Edit?

Subtitle Edit is a free, open-source subtitle editor. It supports 300+ subtitle formats and provides tools for creating, editing, synchronizing, translating, and converting subtitles.

Is Subtitle Edit free?

Yes. Subtitle Edit is released under the MIT license. It is completely free with no ads or limitations.

What platforms does Subtitle Edit 5 run on?

Subtitle Edit 5 is built with Avalonia UI and runs on:

Windows 10 and later
Linux
macOS (Apple Silicon / arm64)

Where is my data stored?

Subtitle Edit stores settings and data in a platform-specific data folder. You can open it via File → Open data folder or the keyboard shortcut.

How do I report a bug or request a feature?

Please open an issue on the GitHub repository.

File Operations

What subtitle formats are supported?

Subtitle Edit supports over 300 subtitle formats including SubRip (.srt), WebVTT (.vtt), Advanced SubStation Alpha (.ass), SubStation Alpha (.ssa), MicroDVD, SAMI, and many more. See Supported Formats for the full list.

How do I convert between subtitle formats?

Open the subtitle file via File → Open
Choose a new format from the format dropdown
Save via File → Save as...

For batch conversion, use Tools → Batch convert....

How do I import image-based subtitles?

Use File → Import image subtitle for OCR... to import Blu-ray SUP, VobSub, or other image-based subtitles and convert them to text using OCR.

You can use File → Import image subtitle for edit... to work/export the images.

Video

What video players are supported?

Subtitle Edit supports:

libmpv — High-quality, wide format support
VLC - Popular player, limited support in SE

Configure the video player in Options → Settings → Video Player.

If you have problems with a video, try Video → More → Re-encode video for better subtitling.

How do I generate a waveform?

Open a video file, and Subtitle Edit will generate a waveform automatically if FFmpeg is installed.

To generate enable spectrogram go to Options → Settings.

Where do I get FFmpeg?

Some functions in Subtitle Edit will prompt for downloading FFmpeg.

You can also download FFmpeg in Options → Settings.

Speech to Text

What speech-to-text engines are supported?

Subtitle Edit supports several Whisper-based engines:

Whisper.cpp — Cross-platform, CPU-based
Whisper.cpp (cuBLAS) — GPU-accelerated (Windows, NVIDIA)
Whisper.cpp (Vulkan) — GPU-accelerated via Vulkan (Windows)
Purfview's Faster Whisper XXL — Fast GPU/CPU-based (Windows, Linux)
CTranslate2 — Fast CPU/GPU-based
Const-me's Whisper — DirectX-based (Windows)
OpenAI Whisper — Original Python implementation
Chat LLM cpp — LLM-based transcription (Windows, Linux)

How do I use Speech to Text?

Open a video file
Go to Video → Speech to text...
Choose an engine and model (download if needed)
Select the language
Click Transcribe

See Speech to Text for details.

Synchronization

How do I fix subtitle timing that is off by a constant amount?

Use Sync → Adjust all times... and enter the offset in milliseconds.

How do I sync subtitles that drift over time?

Use Sync → Visual sync... or Sync → Point sync... to synchronize at multiple points.

How do I convert subtitles between different frame rates?

Use Sync → Change frame rate... and select the source and target frame rates.

OCR

What OCR engines are available?

Tesseract — Open-source OCR engine with language packs
nOCR — Nikse's built-in OCR with trainable databases
Binary OCR — For binary image comparison
Google Lens OCR — Cloud-based
Google Vision OCR — Cloud-based
Ollama OCR — Local LLM-based
Mistral OCR — Cloud-based
PaddleOCR — Local OCR

How do I OCR Blu-ray subtitles?

Open the .sup file via File → Open
The OCR window will open automatically
Choose an OCR engine (Tesseract or nOCR recommended)
Start the OCR process

Spell Check

How do I install spell check dictionaries?

Go to Spell check → Get dictionaries... and download the dictionary for your language. Dictionaries are based on Hunspell/OpenOffice format.

How do I add words to the dictionary?

During spell check, click Add to dictionary to add a word. You can also manage custom words in Options → Word lists.

ASSA / Styling

What is ASSA?

ASSA (Advanced SubStation Alpha) is a subtitle format that supports rich styling including fonts, colors, positioning, animations, and more. It is widely used in anime fansubbing and professional workflows.

How do I edit ASSA styles?

Go to ASSA → Styles... to create and edit subtitle styles with fonts, colors, borders, shadows, and alignment.

Keyboard Shortcuts

How do I customize keyboard shortcuts?

Go to Options → Shortcuts... to view and customize all keyboard shortcuts.

What are the default shortcuts?

See the Keyboard Shortcuts Reference for the complete default shortcut list.

Troubleshooting

Subtitle Edit won't play video

Ensure you have a video player installed (libmpv or VLC)
Check that the video player path is correctly set in Options → Settings → Video Player
Try to re-encode the video for better compatibility via Video → More → Re-encode video for better subtitling

Waveform is not showing

Ensure FFmpeg is installed and the path is set in settings

Speech to Text fails

Ensure the Whisper engine is downloaded (it will prompt you)
Ensure the model is downloaded
Check the console log in the Speech to Text window for error details
Try a smaller model if you run out of GPU memory