Subsai

Whisper-powered subtitle tool with web UI and CLI

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Our take

Subsai wraps Whisper and its faster variants into a usable subtitle generator with web UI, CLI, and Python package — the cleanest single project for running captioning locally without depending on cloud services. Active community, MIT-style license. Setup expects technical comfort.

At a glance

Pricing
Free
Category
Captioning
Price
Free
Platforms
Windows
Best for
Self-hosters running Whisper locally for subtitle generation
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In depth

Subsai is an open-source subtitle generation project that wraps OpenAI's Whisper and its community-maintained faster variants into a coherent toolkit with multiple interfaces. The web UI offers point-and-click transcription suitable for non-developers who can get past the initial install.

The command-line interface enables scripting and batch processing. The Python package allows embedding subtitle generation into larger applications. For self-hosters, privacy-conscious teams, and developers who want to avoid sending audio to a third party, Subsai is one of the cleanest options in 2026.

Faster-whisper, which is bundled as an option, runs roughly four times faster than the reference OpenAI implementation at comparable accuracy and lower memory usage. With a modern GPU, full-episode transcription completes in a fraction of real time.

Without a GPU, expect transcription to run slower than real time, which limits practical throughput. Output covers SRT, ASS, SSA, SUB, JSON, TXT, and VTT formats. Subsai is not a caption stylist — there is no template library, no animated burn-in, no social-style highlight behaviour.

The output drops cleanly into Aegisub or Subtitle Edit for further polish. Setup expects technical comfort: Python environments, dependencies, and optional GPU drivers.

Documentation is community-maintained but generally clear. License is permissive, so embedding in commercial pipelines is straightforward.

Free, from SliceFree subtitle converterSRT, VTT and plain text, converted in the browser. Nothing uploaded anywhere.Open it

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Subsai FAQ

What is Subsai in one line?

Whisper-powered subtitle tool with web UI and CLI

Who should pick Subsai?

Subsai is shaped for self-hosters running whisper locally for subtitle generation. Active community, MIT-style license

Is Subsai free?

Yes. Subsai is free to use. What we have on record: Free.

What can I use instead of Subsai?

Other tools in the same category: Submagic, CapCut, Captions.

Shorts by Slice

From the team behind these free tools

One video. A week of posts.

Upload an episode and get back the moments worth posting, cut and captioned.

  • Reads the whole episode, then picks the excerpts worth posting
  • Captions burned in and framed vertical, ready to post
  • Your first video and first 3 clips are free, no card
Try Shorts by Slice

Maintained by the team behind Podshare. No paid placements, and nobody can buy a listing or a ranking. A few entries are our own products and each one says so.

How we research each tool

Each entry is compiled from the tool’s own homepage and pricing pages, plus public reviews on G2, Capterra, and Trustpilot. Editorial copy reflects our independent take — not the vendor’s marketing language.

We refresh the directory monthly to catch pricing changes and discontinued tools. Last full sweep: May 2026.

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