Sentence mining tools for video, web pages, books and phone

The best sentence mining tool is the one that sits on top of what you already watch or read. If your input is anime, you want a subtitle tool. If it's news, you want something that works on web pages. If it's novels on a Kindle, you want something that turns highlights into cards.

So pick by source first. Then spend your attention on the part no tool does for you, which is choosing the sentences.

What sentence mining is, in one paragraph

You meet a sentence in something you're enjoying. You understand all of it except one word. You look that word up and save the whole sentence, so later you review the word inside the place you met it. Refold calls the ideal case a "1T sentence": exactly one target unknown, everything else familiar. That's the whole method. The tools only change how much friction sits between "I don't know this word" and "it's saved".

If your sentences come from video

asbplayer. Free and open source (AGPL-3.0), a Chrome extension plus a browser-based player. It puts text-selectable subtitles over Netflix, YouTube and your own files, and with Anki and the AnkiConnect add-on it makes cards with the sentence, the audio clip and a screenshot. It also has auto-pause at the end of each subtitle line, which is the single most useful setting for mining.

Migaku. The paid version of the same idea, with its own card system and a browser reader attached. Easier to start, and you pay monthly for it. How it stacks up against the free route is in Migaku vs Yomitan.

If your sentences come from web pages

Yomitan + AnkiConnect. A free pop-up dictionary for the browser, wired to Anki so one key turns the hovered word and its sentence into a card. Best for Japanese, works for many other languages with the right dictionaries. Setup takes an evening.

Sentence Mine. A paid Chrome extension: copy a phrase on any page, and it uses AI to break the sentence down and build the Anki card for you to approve. It expects Anki, AnkiConnect and asbplayer installed alongside it.

Mossglen (full disclosure: ours). A free Chrome extension that skips Anki entirely. Open a page in reading view, tap a word or select a phrase, and it's saved with the sentence it came from. Once you half know a word, the review turns into a fill-in-the-blank on that same sentence, read aloud. No deck, no note type, no card to approve.

If your sentences come from books

VocabSieve. Free, GPL-3.0, desktop. Its best trick: it batch-converts your Kindle or KOReader highlights into Anki sentence cards, so you can read on the e-reader without stopping and mine afterwards. It also lemmatizes (ran becomes run) and, once it knows your vocabulary, estimates how much of a book you'd understand. Tuned for European languages; Spanish, German, English and Russian are the ones its authors test.

If you mine on your phone

jidoujisho. Free and open source, Android only. Reader, video player and dictionary in one app, built for Japanese immersion, with Anki export.

Kimchi Reader. Built for Korean, paid after a 7-day free trial. Select a word in a video or text, hit Mine sentence, and it grabs the word with its full sentence, plus audio and an image when there is one, ready to send to Anki.

Which sentences to mine

Every tool makes saving easy. None of them stops you from saving badly, and that's where most mining habits die.

One unknown, not three. If a sentence has three words you don't know, you don't understand the sentence, so the context does nothing for you. Skip it.

Would you meet it again? A word that shows up in the news every week is worth a card. A sword technique named once in episode 40 isn't.

Short enough to read in one glance. Your future self will read this sentence on a bad day. Twelve words beats forty.

Five to ten per session. Refold's own guide lists mining too many cards as the classic mistake. Thirty new cards a day turns into a review pile you quit by week three. Save the sentences that made you curious, not every gap.

Delete what you already know. If a card comes up and you knew it all along, delete it. Review time is the scarce part.

If you're unsure whether a word deserves the stop at all, these three tests cover it.

Do you need Anki for sentence mining?

Most tools above assume it, because Anki is free, flexible and already where the community lives. If you like tuning decks, it's the strongest option.

If card-making is the part you dread, you have two outs. Use a tool that keeps the sentence and runs the reviews itself, or keep a paper notebook of sentences and reread it. The method is the sentence, not the software. More on that trade in spaced repetition without Anki.

The short version

Your input	Tool	Cost	Needs Anki
Netflix, YouTube, local video	asbplayer	Free	Yes
Video, all-in-one	Migaku	Paid	No
Web pages, Japanese first	Yomitan + AnkiConnect	Free	Yes
Web pages, AI-built cards	Sentence Mine	Paid	Yes
Web pages, no deck	Mossglen	Free	No
Kindle and KOReader highlights	VocabSieve	Free	Yes
Android, Japanese	jidoujisho	Free	Optional
Korean video and text	Kimchi Reader	Paid, 7-day trial	For cards

Then mine less than you think. The words that stick are the ones you meet again while reading.