Grammalecte
Grammalecte is free, open-source software for checking French grammar and typography.
What Grammalecte is
Grammalecte is free, open-source software for checking French grammar and typography. It flags punctuation, spacing, typographic, repeated-word, hyphenation, capitalization, agreement, conjugation, confusion, and pleonasm issues. Users can activate or disable error categories and choose Classic, 1990 Reform, or All Variants spelling dictionaries, with Classic selected by default. Suggestion tools and an OCR option help inspect text produced by optical character recognition. A formatter can address recurring errors and restructure text, while the conjugator covers about 8,000 verbs. Grammalecte is offered as a desktop app and browser extension for Linux, macOS, and Windows. The maker lists integrations for LibreOffice or OpenOffice, Firefox, and Thunderbird, plus a command-line interface, server, and Python package. Its FAQ says analysis occurs on the user’s computer, with no data collection or text transmission. There is no Chrome version compatible with the new extension API. The checker does not perform semantic analysis, can miss mistakes, and may produce false positives.
Good
- Free GPL 3 open-source software
- Broad French error detection
- Configurable dictionaries and categories
- Desktop and browser options
- Local analysis without transmitted text
Watch out
- Supports one language
- No current Chrome new-API extension
- No semantic analysis
- Can miss errors and produce false positives
Who it suits
It suits French writers who want local grammar and typography checking across desktop, browser, office-suite, or command-line environments. It is useful for users who prefer free GPL 3 software and offline text analysis.
Verdict
Grammalecte offers extensive French-focused correction with local processing and many integration options at no cost. Its language scope, Chrome limitation, and inability to assess meaning define where it fits.
Plans and prices
From Grammalecte's own pricing page, checked 15 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Free | Free | Open-source software · French grammar and typography correction · donations requested |
| Grammalecte | Free | Open-source software; French grammar and typography correction |
The facts
Each one read from Grammalecte's own pages, with the date it was checked.
Where it runs
- Browser extension
- Yeschecked 20 Sep 2026
- Desktop app
- Yeschecked 20 Sep 2026
What it does
- Chrome limitation
- The official site says there is currently no Grammalecte version compatible with Chrome’s new extension API.checked 15 Oct 2026
- Chrome support
- The maker says there is currently no Grammalecte version compatible with Chrome’s new extension API.checked 8 Oct 2026
- CLI capabilities
- Debian’s man page documents file checking, JSON error output, text formatting, personal dictionaries, suggestions, rule listing and option toggles.checked 15 Oct 2026
- Conjugator
- Its conjugator covers about 8,000 verbs contained in the dictionary.checked 15 Oct 2026
- Current version
- The official site lists version 2.3.0, released 15 December 2025.checked 15 Oct 2026
- Custom dictionary
- A lexical editor lets users create a personal dictionary.checked 15 Oct 2026
- Data handling
- The FAQ says Grammalecte collects no data, analyzes writing on the user's computer, and transmits no text.checked 8 Oct 2026
- Developer distribution
- The project publishes a command-line interface, server and Python package requiring Python 3.7 or newer.checked 15 Oct 2026
- Dictionaries
- It supplies Classic, 1990 Reform and All Variants French spelling dictionaries, with Classic selected by default.checked 15 Oct 2026
- Error detection
- The checker covers punctuation, spacing, typography, redundancy, hyphenation, capitalization, gender and number agreement, conjugation, homonyms, false friends, pleonasms and optional OCR errors.checked 15 Oct 2026
- False-positive strategy
- Its stated design goal is to minimize false alerts and remain silent when an error cannot be identified confidently.checked 15 Oct 2026
- Firefox privacy
- The official site says the Firefox module sends no information online.checked 15 Oct 2026
- Firefox security
- The Firefox add-on is signed, its code is checked by Mozilla, and the maker says it sends no information online.checked 8 Oct 2026
- Grammar controls
- Users can enable or disable individual categories of grammatical checks.checked 15 Oct 2026
- Implementation
- The core is written primarily in Python and translated into JavaScript for browser and Thunderbird extensions.checked 15 Oct 2026
- Integrations
- Official integrations include LibreOffice, OpenOffice, Firefox and Thunderbird; community plugins exist for Sublime Text, Vim, Emacs, GEdit, Pluma and Sigil.checked 15 Oct 2026
- Known limitations
- The official site warns that false positives cannot be eliminated, overlapping Writer errors can apply a correction to both regions, and superscript or subscript text may be disturbed.checked 15 Oct 2026
- Languages supported
- 1checked 20 Sep 2026
- Lexicographer
- The lexicographer identifies the grammatical nature of the word at the cursor.checked 15 Oct 2026
- LibreOffice requirements
- The current LibreOffice extension targets LibreOffice 6.4 and newer; older builds cover earlier LibreOffice and OpenOffice releases.checked 15 Oct 2026
- LibreOffice tools
- The LibreOffice integration includes a word counter and a tool for changing Writer’s author field.checked 15 Oct 2026
Money
- Free plan
- Yeschecked 20 Sep 2026
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