AI Review

Proofread the subtitle text with a local (or remote) large language model - typos, spelling, grammar, punctuation and casing. Nothing is changed until you apply the suggestions you agree with.

• Menu: Tools → AI review...
• Shortcut: Ctrl+Alt+R (Cmd+Alt+R on macOS)

<!-- Screenshot: AI review window -->

Engines

• llama.cpp — a managed local server. Pick a model from the curated list (Qwen 3.5, Gemma 3, Llama 3.1, EuroLLM, Phi-4 mini); Subtitle Edit downloads the engine and model on first use. A green dot marks models that are already downloaded. Custom *.gguf files placed in the llama.cpp models folder also appear.
• Ollama — uses a running Ollama instance; type a model name or pick one from the server.
• OpenAI-compatible — any endpoint that speaks the OpenAI chat API: LM Studio, KoboldCpp, vLLM, a llama.cpp server on another machine, or cloud APIs (OpenAI, Groq, OpenRouter, DeepSeek, Mistral, Gemini). Enter the URL, model name, and an API key if the service needs one.

Reviewing

Press Review to start. The subtitle is sent to the model in small batches, and suggestions appear in the grid while the review runs - you can inspect, check and uncheck rows before it finishes, or press Stop to keep what was found so far.

Each suggestion shows:

• Apply — checkbox deciding whether the fix is applied
• Line number and a category tag (spelling, grammar, punctuation, casing, other)
• Before / After — with word-level differences highlighted
• Selecting a row shows the model's short reason below the grid

Filter the grid with the category chips above it. Press Apply N fixes to apply the checked suggestions - this is a single undo step (Ctrl+Z reverts everything).

Sentences across multiple lines

Lines are grouped into sentence units, so a sentence that continues over several subtitles is always reviewed as a whole, and the model sees a couple of surrounding lines as read-only context. Corrections never move words between lines, so timing and reading speed are unaffected. Suggestions belonging to the same sentence are checked and unchecked together.

The prompt

The Edit prompt... button opens the review instructions sent to the model. {language} is replaced with the auto-detected subtitle language. The strict data-exchange contract is appended by Subtitle Edit and cannot be broken by prompt edits, so feel free to tailor the instructions - e.g. "also flag anachronisms" or "never touch song lyrics".

Safety rails

• Nothing is applied automatically - you decide per suggestion.
• Suggestions that would add or remove formatting tags are discarded.
• Suggestions that change a line's length a lot are flagged with a warning and start unchecked, since they are usually rewrites rather than corrections.
• Replies from the model that do not follow the expected format are retried once and then skipped.