SubSmith turns local video and audio files into Anki-ready language lessons

SubSmith lands on Hacker News with a file-based learning pitch

A tool named SubSmith reached Hacker News's front page on 28 August 2026, positioned as a way to learn languages from media you already own. Instead of working on top of streaming platforms, it processes local video and audio files, generates subtitles for them and turns the result into study material.

According to the product's site, the workflow has three steps. You start by dropping in a file — MKV, MP4 and MP3 are among the supported formats — and the app generates subtitles that are already aligned with the media, removing the usual chore of fixing timing offsets. A hover dictionary then shows a definition for any word without pausing playback, which the makers say keeps learners engaged with the content instead of interrupting it to consult a translation app. Finally, sentences can be captured with a single click: audio clips, screenshots and definitions are exported to Anki, the popular open-source flashcard program, with the site suggesting one video can yield enough cards for roughly a week of review.

Features and language coverage

The feature list goes beyond that core loop. SubSmith advertises support for more than 99 languages, editable timestamps and transcripts, and subtitle export in either SRT or plain-text format. The editing tools matter because automatic transcription is never perfect — with coverage this broad, recognition quality will presumably vary from language to language, though the site does not break down accuracy by language.

Pricing and the lifetime-licence caveat

SubSmith is offered as a seven-day free trial with no credit card required, an annual plan at $15 per year, and a one-time $40 lifetime licence described as the best value. The fine print on the lifetime option deserves attention: the licence itself does not expire, but compatibility, updates and online services are tied to what the site calls the supported lifetime of the product. In practice, features that depend on the maker's servers could stop working even for lifetime buyers — a caveat that has become familiar with one-time-purchase software that retains online components.

Built for local media libraries

Two guides published alongside the product clarify who it is for. One explains sentence mining from downloaded shows, podcasts and MKV files. The other frames SubSmith as an alternative to Language Reactor, the widely used browser extension, and walks through the tradeoffs between desktop and browser workflows around local files, crashes and offline study. That framing points at learners whose immersion libraries live on disk rather than inside a streaming subscription, and at users who have run into the instability or platform limits of extension-based tools.

Why it matters

Sentence mining — collecting real sentences spoken by natives and drilling them as flashcards — has become a cornerstone of immersion-based language learning, but the tooling around it is fragmented. Browser extensions work well on streaming sites yet poorly, or not at all, on personal media collections, and building an offline pipeline normally means chaining together a transcription tool, a dictionary lookup and manual Anki card construction. SubSmith bundles that pipeline into a single app, and that integration is the genuinely notable part of the launch rather than any one feature.

There are caveats to keep in mind. Every claim here comes from the maker's own marketing page — there is no independent verification of subtitle accuracy, dictionary quality or how reliable the Anki export is in practice, and the Hacker News comment thread was not part of the material reviewed. The trial is free and the paid tiers are inexpensive, so evaluating it firsthand is low-risk, but the lifetime licence's dependence on the product's supported lifetime is a reminder that one-time purchases of software with online services attached are never entirely one-time.