ioDiacritics

ioDiacritics restores stripped Latin diacritics in Bosnian, Croatian and Serbian text — ć, č, đ, dž, š, ž. Turn citaj sa uzitkom back into čitaj sa užitkom. It's deterministic and AI-free: bundled dictionaries, no ML model, no server, completely offline.

For apps, scripts and text pipelines that need reliable citaj → čitaj restoration without calling an API — license the library and ship.

Two libraries, one engine

• A SwiftPM package for macOS and iOS (Swift 5.9+).
• A portable C++17 library for Windows, Linux and macOS.
• Same engine, dictionaries and quality metrics across both.

Measured quality

• Three language packs — Bosnian 94.9% recall, Croatian 96.1%, Serbian 93.7%.
• ~99.5–100% edit precision: it rarely changes a word it shouldn't.
• Montenegrin covered in compatibility mode.
• Validated on 10,000+ documents using bootstrap confidence intervals.

Demo apps

The ioDiacritics-Demos repository ships three self-contained showcases that link the same engine: a SwiftUI desktop app for macOS, a system input method (Šišana — below), and a cross-platform C++ app (Dear ImGui + GLFW + OpenGL3) for Windows, macOS and Linux. Same dictionaries and quality numbers across all three.

In production: Kvačice.com — a free web tool that does the same job for readers instead of developers: paste bald Latin, get č ć š ž đ back, entirely in the browser and offline after first load. Handy to point someone to when they need the result rather than a library.

The hard part of this job isn't adding diacritics — it's knowing when not to. In odjek, predjelo, odjednom and adjektivizacija the dj is two letters and must never collapse into đ, while rodjendan must. The engine ships an explicit protect list for exactly these; the cases themselves, and why native speakers argue about them, are written up at kvacice.com/dj-ili-dj.

⌨️ ioDiacritics Šišana — type with diacritics, anywhere

The newest showcase turns the engine into a macOS input method — a system input source you pick from the keyboard menu, just like a layout. Type bald Latin in any app and the diacritics appear as you go (citaj → čitaj): no window, no copy-paste, no Accessibility permission, fully offline. When a word is genuinely ambiguous it pops a Chinese-style candidate list — casa → časa · čaša · ćasa — so you pick the right reading with a number key, while confident words just restore themselves. It's the most natural way to write šišana Bosnian/Croatian/Serbian: keep typing the easy way and let your text come out correct.

✓ Signed & notarized · macOS 13+ · .pkg ≈4.8 MB. Run the installer — choose Install for all users (admin password → system-wide) or Install for me only (no admin). Then add Šišana in System Settings → Keyboard → Input Sources → ＋ (listed under Serbian (Latin)) and pick it from the menu-bar input menu. Provided “as is”, without warranty — see terms.

Also powers diacritics restoration inside PolyType — or use it online, no install: polytype.app (Serbian · Croatian · Bosnian, right in the browser).