LibreOffice, the free and open-source office suite, can be enhanced with extensions (add-ons) available from the official LibreOffice Extensions repository at extensions.libreoffice.org. These extensions add features like improved spellchecking, AI tools, diagramming, budgeting templates, and more. They are typically packaged as .oxt files, installable via Tools > Extension Manager in LibreOffice, and most are compatible with LibreOffice 7.0+ (check individual pages for specifics). Below is a curated list of 15 popular extensions based on download counts, ratings, and utility, drawn from the repository and community recommendations. I’ve included details on category, key features, and installation notes where relevant. Extension Name Category Description & Key Features Compatibility Downloads/Rating English Dictionary Writer (Spellcheck) Provides comprehensive English language dictionaries for spellchecking, hyphenation, and thesaurus support in documents. Ideal for writers needing accurate language tools. LibreOffice 4.0+ 81,197 downloads / ★★★★☆ Yaru Icon Theme General (UI Customization) A full-color icon pack based on Ubuntu’s Yaru theme, replacing default icons for a modern, consistent look across Writer, Calc, Impress, and more. Variants include blue and Prussian green. Recent versions (7.0+) 10,008+ downloads / ★★★★★ UML Elements Draw (Diagramming) Adds galleries of visually consistent elements for creating UML (Unified Modeling Language) diagrams, such as class, sequence, and use case diagrams. Great for software developers and engineers. Recent versions 9,722 downloads / ★★★☆☆ localwriter Writer (AI Assistance) Integrates local-inference generative AI directly into Writer for tasks like text completion, summarization, and idea generation without cloud dependency. Recent versions 7,786 downloads / ★★★★☆ Monthly Budget and Expense Record Calc (Financial Tools) A customizable spreadsheet template for tracking expenses using the “envelope” budgeting method. Supports category creation, transaction pasting from banks, and automatic balance calculations. Recent versions 6,511 downloads / Not rated LibreMacro Calc (Macros/Automation) A library of pre-built macros to automate tasks like data formatting, cell manipulation, and report generation, boosting efficiency for spreadsheet-heavy workflows. Recent versions 4,294 downloads / Not rated AI Images for LibreOffice General (Image Generation) Generates images from text descriptions using AIHorde (a distributed AI network), allowing direct insertion into Draw, Impress, or Writer for quick visuals. Recent versions 4,587 downloads / Not rated Lime Theme General (UI Customization) Applies a vibrant lime-colored theme to the LibreOffice interface, including toolbars and menus, for a fresh, eye-friendly alternative to defaults. Recent versions 1,977 downloads / ★★☆☆☆ Ancient Greek Spellchecker Writer (Spellcheck) Adds spellchecking and hyphenation support for Ancient Greek texts, essential for academics, historians, or linguists working with classical languages. LibreOffice/OpenOffice 2,129 downloads / ★★★☆☆ British English Spell Checker (Darmeth) Writer (Spellcheck) A strict dictionary enforcing preferred British English spellings (e.g., “colour” over “color”), with support for hyphenation and thesaurus. Recent versions 2,245 downloads / Not rated TexMaths Writer/Math (Equation Editor) Integrates LaTeX equation editing, allowing insertion of complex mathematical formulas as editable SVG or PNG images. Perfect for scientific documents; requires Java. Recent versions (Java required) High community use (from external sources) / ★★★★☆ Zotero LibreOffice Integration Writer (Citation Management) Connects Zotero (a free reference manager) to Writer for seamless insertion of citations, bibliographies, and notes in thousands of styles (e.g., APA, MLA). Supports multi-page citations and custom formats. Recent versions Popular in academia / ★★★★★ LanguageTool Grammar Checker Writer (Grammar) Advanced grammar, style, and punctuation checker supporting 20+ languages. Detects complex errors like awkward phrasing; runs locally or via server. Note: May cause occasional crashes in older versions. Recent versions Widely recommended / ★★★★☆ Alternative Dialog Find & Replace Writer (Search Tools) Enhances the built-in Find & Replace with regex support, multi-line searches, and options for bookmarks, footnotes, and tables. Essential for editing long documents. Recent versions Community favorite / ★★★★☆ Calendar for Calc Calc (Date Tools) Adds a pop-up calendar for quick date insertion in cells, supporting ISO format and range selection. Simplifies data entry for reports and schedules. Recent versions Useful for daily users / ★★★☆☆
Additional Notes
- Installation: Download .oxt files from the repository, then in LibreOffice, go to Tools > Extension Manager > Add. Restart the app after installation. Some require Java (enable via Tools > Options > LibreOffice > Advanced).
- Categories Breakdown: Writer-focused (e.g., spellcheck, AI) make up ~40% of popular extensions; Calc ~30%; General/UI ~20%; Draw/Impress ~10%.
- Sources & Exploration: This list prioritizes highly downloaded items from the official site. 37 For more, filter by category on the site or check community lists. 3 22 26 Always verify compatibility with your LibreOffice version (current as of October 2025: 25.x series). If you need details on a specific extension, provide its name!