AI Clean Up

AI Clean Up is a separate feature from the offline Cleanup tool — it uses DeepSeek's AI over the internet to actually rewrite subtitle text for grammar and fluency, rather than pattern-matching known junk out of it. It only rewrites text; timings are never touched.

Before you start

The AI Clean Up button only appears in the editor header if a DeepSeek API key is saved in Settings → AI Providers — without one, the button isn't shown at all, not just disabled. Like AI translation, this feature requires an internet connection and uses your own DeepSeek usage.

The three modes

Fix ErrorsCorrect grammar, spelling, ASR mishears and misrecognised names, with minimal rewrites.
Improve FlowFix errors and also rewrite awkward or hard-to-follow sentences so they read naturally.
PolishFull cleanup: fix errors, improve flow, tighten wording, and refine dialogue rhythm.

Context hint and batching

An optional Context hint field (e.g. a show or franchise name) helps the AI recognize character names and franchise-specific terminology — the same idea as the Translate screen's context field. Batch size (1–50, default 10) and Parallel batches (1–10, default 3) control how subtitles are chunked and sent to DeepSeek concurrently.

Running it

Click Start AI Clean Up. A progress screen shows the current phase, a per-subtitle progress bar, and a per-batch progress bar. When it finishes, a "Cleanup Complete" screen shows how many subtitles were cleaned and either the filename it auto-saved to, or a warning if there was no source path to save to (in which case use Export to save manually).

The result stays unsaved in the editor (marked "dirty") until you explicitly Save or Export, and — like every other edit — can be undone with ⌘Z.

FAQ

Why don't I see the AI Clean Up button?
You need a DeepSeek API key configured first. Go to Settings → AI Providers.
Does this change my subtitle timing?
No — only the text of each cue is rewritten. Timestamps are untouched.
When should I use this instead of the regular Cleanup tool?
Use the regular Cleanup tool first for structural junk (SDH tags, credits, encoding). Reach for AI Clean Up when the actual wording needs improving — most commonly on AI-transcribed subtitles with ASR mistakes, or dialogue that reads awkwardly.
Does AI Clean Up cost money?
AI Subtitle Studio doesn't charge for it — DeepSeek bills your own API key directly at their usage-based rates.