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Offline dictionary with spaced repetition (Tauri, Svelte): Deft

Offline dictionary with spaced repetition (Tauri, Svelte): Deft

by L_i_m_n·Mar 1, 2026·2 points·1 comment
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AI Analysis

●●SolidCozySolve My ProblemNiche Gem

Full Wiktionary offline with FSRS spaced repetition and OCR; no ads, no internet required.

Strengths
  • •Three-tier search (full-text Tantivy + prefix SQLite LIKE + fuzzy edit distance) is fast enough for search-as-you-type.
  • •Compressed Wiktionary from 18GB to ~220MB without losing definitions; 100MB target for next release shows thoughtful engineering.
  • •OCR lookup while reading solves real friction: tap words on pages to define without context-switching.
Weaknesses
  • •Android not yet released; iOS-only limits addressable audience today.
  • •Crowded space: Anki, Quizlet, Duolingo, Memrise already dominate vocabulary+spaced repetition; offline is niche differentiator.
Category
Productivity
Target Audience

Language learners, casual readers, accessibility-focused users wanting offline-first vocabulary building

Similar To

Anki · Quizlet · Duolingo

Post Description

i needed a vocab app that worked offline with spaced repetition built in. the options out there either required an internet connection, didn't have spaced reptition, or has ads.

deft ships the entire English Wiktionary (~1.1M words) on-device. the raw Wiktionary dump is ~18GB of JSONL — i stripped it down to just the basics (glosses, parts of speech, related words) and compressed it into a ~220MB SQLite database for definitions and a ~34MB Tantivy search index. next release should bring the total size down to ~100MB, just finalizing that.

search runs three tiers via Rust: full-text search through Tantivy, prefix match via SQLite LIKE sorted by word length, then fuzzy match with 2-char edit distance. results get deduplicated and merged. fast enough for search-as-you-type.

there's also OCR. you can point your camera at a page and tap words to look them up. useful for getting a defintion when books and gradually saving words without breaking focus.

flashcards use FSRS (Free Spaced Repetition Scheduler) through ts-fsrs. nothing fancy, just enough to make words stick.

works entirely offline, no account needed. iOS only right now.

https://deft.so/

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