Translate & Lookup
Readest can translate a selection, look up a word in Wiktionary, or pop up the Wikipedia article — all without leaving the page.
Translate a selection
Select any text and pick Translate from the annotation toolbar, or press Ctrl+T / Cmd+T. A popup shows the translation alongside the original. You can copy either side, or dismiss the popup and keep reading.
Readest auto-detects the source language. Pick the target language from the popup; Readest remembers your last choice per book.
Translations are ephemeral by default — they disappear when you dismiss the popup. To keep one, annotate the selection first (Ctrl+N) and paste the translation into the note.
Translation providers
Switch provider under Settings → Translation → Provider.
- DeepL — widely considered the most natural-sounding translator for European languages.
- Microsoft Translator — solid all-around choice with a large language catalog.
- Google Translate — good for a wide variety of languages, especially outside Europe.
Daily usage limits apply to cloud providers. Readest shows remaining quota on the settings screen; if you hit a limit, switch to a different provider or wait for the daily reset.
Dictionary & Wikipedia
Dictionary. Select a single word and press Ctrl+D / Cmd+D, or tap Dictionary in the annotation toolbar. Readest looks the word up across every enabled provider — Wiktionary, Wikipedia, any custom dictionaries you've imported, and any web search providers you've added — and shows the results as a stack of cards. Tap a card header to expand or collapse it. If the exact word isn't found, Readest automatically retries with its base form, so looking up running or mice still turns up run and mouse (English today).
Wikipedia. Select a word or phrase and press Ctrl+W / Cmd+W, or tap Wikipedia. A Wikipedia article summary opens in a popup.
Dictionary and Wikipedia lookups are single-language by design — they follow the language of the selection, not your reading language.
Custom dictionaries
Wiktionary and Wikipedia are built in. Beyond those, you can plug in your own dictionary files or any web-based dictionary or search engine.
Open the manager from Settings → Language → Dictionaries, or tap the gear icon at the top of any dictionary popup.
System Dictionary. At the top of the providers list, turn on System Dictionary to hand lookups to your operating system's own dictionary instead of Readest's in-app popup — the macOS Look Up panel, the iOS / iPadOS dictionary sheet, or Android's "process text" chooser (which offers whatever dictionary or translation apps you have installed). It's available on macOS, iOS, iPadOS, and Android (not on web, Windows, or Linux), and it's off by default. While it's on, the other providers are locked, since every lookup goes straight to the OS.
Offline bundles. Tap Import Dictionary and select all the bundle files together — large dictionaries now import and look up much faster. Supported formats:
- StarDict —
.ifo,.idx, and.dict.dz(optional.syn). - MDict —
.mdx, with optional.cssand one or more.mddresource files. Companion.mddfiles that share the.mdxname (Name.mdd,Name-01.mdd, …) are attached automatically — just select them all together. - DICT —
.indexplus.dict.dz(a raw, un-zipped.dictalso works). - Slob —
.slob.
Imported bundles appear in the providers list. Drag to reorder, toggle on/off, rename, or delete.
Web Search. Tap Add Web Search to add any URL-based lookup. Give it a name and a URL template that contains %WORD% — Readest substitutes the selected word at lookup time. Examples:
https://www.google.com/search?q=%WORD%https://www.merriam-webster.com/dictionary/%WORD%https://dict.naver.com/search.dict?query=%WORD%
Web Search results open inline in the same stacked-card view.
Whole-book translation
For extended passages, or a whole book in a language you're learning, enable book translation mode from the reader menu. This translates paragraphs inline as you scroll, showing the translation below each original paragraph.
Notes:
- Network-bound: every new paragraph sends a request to your chosen translation provider.
- Respects your provider setting. Book-translate makes many requests, so high-quality translators with generous daily quotas (DeepL Pro, AI Gateway) suit it best.
- Reading position and annotations still work the same — only the display changes.
Turn it off again from the same menu when you want to read monolingually.
Word Lens
Word Lens prints a small native-language hint above the words it reckons are hard for you, so you can stay in the original language and only glance up when you need to. The hints render as ruby text above each word — like Japanese furigana, but for meaning.
Turn it on under Settings → Language → Word Lens:
- Enable Word Lens — the master switch (set per book).
- Level — your reading level on the CEFR scale (A1–C2). A lower level hints more words; a higher one hints only the rarest.
- Language — the language the hints appear in (Auto follows your interface language).
- Hint size and Hint color — style the gloss above the word.
Hints come from small per-language data packs. With Auto-download on (the default), Readest fetches the pack it needs over an unmetered connection; otherwise grab it yourself from the Data pack row. Word Lens works wherever the source language can be split into words — Chinese and space-separated languages are supported; Japanese, Korean, and Thai are not.