Sluka

Get past the wall of blue

Chinese text is dense with function words you already know. Mark the most common words as known in one go, then let reading fill in the rest. This only touches words still marked new — anything you have already graded is left alone.

Dictionary

Checking…

How the colours work

Click a new word to start learning it, then grade it 1–4 as it becomes familiar. The highlight fades at each level and disappears at Known. The last colour is Chinese only: the word is new in the script you are reading, but you already know it in the other one.

Smart tracking

Count time spent listening to Chinese Once a minute, Sluka checks which tab is making noise and whether what is playing is in the language you are learning. Time is credited against the track's own clock, so a paused or silent tab counts for nothing. Ask when a title does not say which language it is Plenty of shows are made in one language and titled in another — Chinese podcasts with English episode names, Italian courses aimed at English speakers. Their time is measured and held either way; this asks you, once the track ends, whether to count it. Answer once and the whole show is remembered.

Browser tabs only. An extension can see what is playing in a tab — YouTube, the Spotify web player, a podcast site — and nothing outside the browser. Audio from the Spotify desktop app or any other program is invisible to it. The phone has no such limit: it counts whatever is playing anywhere.

Today

0s

Counted only while a track judged Chinese was playing. Time held for an answer is not in this total.

Added up about once a minute, when Chrome next wakes the extension — so this can read a little behind the tab that is playing. The time in between is still being measured.

Their titles do not say which language they are in, so the time is measured and held here rather than counted. Answer once and the whole show is remembered.

Nothing heard yet. Play something in a tab and it will show up here.

Kept for a year. Removing a track does not change the time counted — the totals above and the daily log are counted separately, and forgetting what you listened to must not rewrite how long you listened for. A show judged wrongly can be corrected here, and the answer is remembered for every episode of it from then on.

Licence

Reading

Enable the readerHighlight words on the pages you visit. Language switcher while reading Puts the flag in the counter island on every page, so the language can be changed without opening this dashboard. Off by default — the island is deliberately the smallest thing on the page. Preview on hoverShow the reading and meaning without clicking. Hover delay

Clicking a new word starts learning itMatches LingQ: blue turns yellow on click. Links stay clickableOn a word inside a link, a normal click follows the link and Shift+click opens the word instead. Turn this off to make every click open the word. Build words by selecting charactersDrag across characters the segmenter split wrongly to look them up and save them as one word. Nothing is saved until you pick a level. Only highlight text that looks ItalianThis language is written in the same alphabet as the navigation, the cookie banner and the byline around it, so every word is checked against the dictionary and a paragraph is only read if enough of it belongs to the language. Turn this off if you read pages that mix two languages inside one paragraph — then everything is highlighted, and "know all on this page" will file the other language's words as ones you know. Grade by hoveringPoint at a word and press 1–4, K or X — no click, no popup to close. Show the page counterSmall badge with new/seen counts and a "know all" button. SlukaCCWhile you are on a subtitle or its translation, pause before that line disappears. Leave both and the video plays again. Also gives the arrow keys to the caption line, so its words can be stepped through and graded without the mouse. Toggled from a button inside the player on YouTube, Netflix and similar sites. Readings above the characters Prints each word's reading over the text itself — kana over the kanji and never over the okurigana beside it, pinyin or zhuyin over Chinese, jyutping or Yale over Cantonese. Lines grow taller to make room, so a page is laid out a little differently while this is on. Which notation each language uses is set in its own card below. Show them over Words you are still learning — blue and yellow New words only — blue Every word A reading you no longer need is a reading in the way. Marking a word known takes its reading off the page at once, and the line keeps its height, so nothing below it moves. PDF books Fit to the screen on a phone Always the printed page Always fit to the screen Fitting recovers the page's text into paragraphs at a readable size and keeps its pictures, so a book scrolls down instead of being dragged sideways. The button in the reader's toolbar switches the book you are in and changes this.

Chinese

Read simplified and traditional as one language A word spelled the same in both scripts already counts as one word, whichever you meet it in. This is about the ones that differ: meeting 开始 when you already know 開始 marks it in its own colour rather than leaving it in the wall of blue. Both on such a word — or plain K — files the two spellings as one known word; the pair never counts twice. Transliteration Pinyin Zhuyin (bopomofo) Both None Readings above the characters Pinyin — tái wān Zhuyin — ㄊㄞˊ ㄨㄢ Used only when readings above the characters are switched on, under Reading. One notation at a time — two of them stacked over a single character is unreadable at that size, which is why Both is offered for the panel and not here. Translate into English The bundled dictionary is Chinese → English. Other target languages need an online translation service, which this version deliberately does without so nothing leaves your machine.

Cantonese

Read simplified and traditional as one language The same setting Chinese has, and it applies inside Cantonese on the same terms: meeting 开始 when you already know 開始 marks it in its own colour. It never links across the two languages — knowing a word in Mandarin is not knowing it in Cantonese, which is why they are separate here at all. Transliteration Jyutping Yale Both None Jyutping is the Linguistic Society of Hong Kong's standard and what current dictionaries use; Yale is what many older textbooks were written in. Same sounds, different spelling — nei5 hou2 and néih hóu. Readings above the characters Jyutping — nei5 hou2 Yale — néih hóu Used only when readings above the characters are switched on, under Reading. Translate into English The bundled dictionary is Cantonese → English, built from CC-Canto and CC-CEDICT with readings and word frequencies from rime-cantonese.

Japanese

Transliteration Romaji — tōkyō Hiragana — とうきょう Katakana — トウキョウ None How a word's reading is written in the panel. Romaji is modified Hepburn, the spelling used on road signs and in passports, with long vowels marked — ō is two beats, o is one. Readings above the characters Hiragana — としょかん Katakana — トショカン Furigana is kana over kanji, so romaji is not offered here — Latin letters above a character are a gloss rather than a reading, and the panel above is where a romaji reader is served.

Korean

Transliteration Revised Romanization — hangungmal Both — 한국말 hangungmal None Hangul is an alphabet, so you can sound a word out once you have learned it — but it spells the parts of a word rather than the sounds, and the two differ: 한국말 is written han-guk-mal and said hangungmal. The romanization is the said version, in the official spelling used on road signs and in passports.

AI check for unknown words

CC-CEDICT misses new coinages, slang and proper nouns. When a word has no entry, this asks Claude whether it is genuinely a word — and it can answer "not a word", which is often the correct answer.

Enable the AI check Adds an "Ask AI" button to words with no dictionary entry. Nothing is sent until you press it. Anthropic API key Stored locally in this browser and only ever sent to api.anthropic.com. Get one from console.anthropic.com. Entering one switches the check on. Workspace ID — usually leave empty Only for a key that covers more than one workspace — most do not, and a key that does not must leave this empty. If a check comes back asking for a workspace ID, copy the wrkspc_… value from Settings → Workspaces in the Anthropic console. Model Claude Opus 5 — most capable Claude Sonnet 5 — faster, cheaper Include the surrounding sentence Lets the word be judged in context. Turn off to send only the word itself.

This is the one feature that leaves your machine. Everything else — highlighting, the dictionary, your vocabulary — stays local. Each check costs roughly a US cent on Opus 5, billed to your own API account.

Colours

Underline instead of fillEasier on image-heavy pages.

Keyboard

Click a shortcut, then press the keys you want.

Never run on

One hostname fragment per line.

Sync with your other device

Your words, statistics, books and listening time keep themselves up to date between this computer and your phone whenever both are on the same wifi. Nothing goes near the internet — the two talk to each other directly.

Send book files too Not just your place in a book, but the book. It goes over the same wifi, a piece at a time, and picks up where it stopped if you close the laptop halfway through. Largest book to send (MB) Anything bigger stays on the device it was added to, and the shelf says so. 0 means no limit.

Automatic backup

A second copy of your vocabulary, statistics, shelf and listening history, kept somewhere uninstalling cannot reach. It is written by itself as you read — there is nothing to remember to do.

Bring your words over from LingQ

Export your vocabulary from LingQ as CSV and open it here. Your words arrive with the meanings you gave them, and those show on the Words tab — including for words the dictionary has never heard of.

Only known words can be imported. A LingQ export says nothing about how well you know anything: there is no level in the file, and nothing to work one out from. So everything in it is filed as Known, and a file with words you are still learning in it would claim you know them. Export a known-words list, not your whole vocabulary.

Your data

Everything is stored locally in this browser. Keep a backup.