Lexiathan™Overview
Lexiathan delivers real-time spelling correction in the browser at speeds up to 380× faster than Hunspell, while remaining lightweight, deterministic, and highly accurate, even on severely misspelled words.
Built as a single, compact WebAssembly binary, Lexiathan is designed for web applications that demand speed, correctness, and control.
Features
Extreme performance
In benchmark testing, Lexiathan runs hundreds of times faster than Hunspell, with consistently low latency even at p95. This makes it suitable for real-time use in editors, forms, and document pipelines where traditional spell-checkers choke. On real-world documents, Lexiathan consistently processes 100,000–1,000,000 words per second, entirely in the browser.
| Lexiathan (TinyGo) | Hunspell-ASM (C++) | SymSpell-WASM (Rust) | |
|---|---|---|---|
| Median | 0.10 ms | 38.6 ms | 0.50 ms |
| p95 | 0.30 ms | 52.8 ms | 0.80 ms |
| Average | 0.14 ms | 37.9 ms | 0.54 ms |
Superior accuracy
Conventional spell-checking engines fail once a word is heavily corrupted. Lexiathan, however, can recover correct spellings at Levenshtein distances of 6 or more, without any significant performance degradation. This allows it to handle real-world input, including typos, OCR errors, and severely misspelled words that other spell-checkers fail to accurately correct or miss entirely.
| Word (misspelled) | Lexiathan (TinyGo) | Hunspell-ASM (C++) | SymSpell-WASM (Rust) |
|---|---|---|---|
| pronnouncaition | ✅ pronunciation | ✅ pronunciation | ❌ none |
| inndappendent | ✅ independent | ✅ independent | ❌ none |
| maggnificntally | ✅ magnificently | ✅ magnificently | ❌ none |
| annnesteasialgist | ✅ anesthesiologist | ✅ anesthesiologist | ❌ none |
| unegspeccted | ✅ unexpected | ⚠️ “unsuspected” (wrong top hit) | ❌ none |
| soggtwaee | ✅ software | ⚠️ “sogginess” (wrong top hit) | ❌ none |
Flexible dictionary control
Lexiathan supports dynamic dictionary management, allowing words to be added or removed as needed. This makes it well-suited for domain-specific vocabularies, technical writing, legal documents, and organizations that require precise control over accepted language.
Privacy-first, fully local execution
Lexiathan runs entirely client-side and never phones home. There is no telemetry, no background network activity, and no dependency on external services. All spell-checking is performed locally, making Lexiathan suitable for privacy-sensitive, offline, or security-restricted environments.
Lightweight, allocation-free runtime
Lexiathan is built as a compact 5 MB WebAssembly (WASM) binary. Its runtime performs zero heap allocations during spell-checking and is completely garbage-collection free, ensuring predictable performance and consistently low latency even under sustained load.
Easy integration
Lexiathan's API supports full document ingestion, allowing entire texts to be analyzed in a single pass. This simplifies integration and enables high-throughput, low-latency spell-checking for large documents.
For each misspelled word, Lexiathan provides precise character offsets, enabling accurate highlighting and inline correction in editors, viewers, and document processing pipelines. This makes it straightforward to map corrections back to the original text.
Lexiathan accepts Unicode text without special configuration. This makes Lexiathan suitable for modern, internationalized content and avoids edge cases common in legacy spell-checking libraries.
Try Lexiathan
Experience the speed and accuracy of Lexiathan firsthand with a fully-featured demo.
The evaluation binary includes full access to the spell-checking engine for 14 days and two demo applications, enabling you to measure performance, accuracy, and integration effort directly. The evaluation binary runs entirely locally, does not require network access, and contains no telemetry.