Power Thesaurus by Power Thesaurus
Use the power of synonyms by button in toolbar, right-click or by word selection on any page.
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About this extension
Enhance your writing with the Power Thesaurus extension from PowerThesaurus.org — a comprehensive, fast, and user-friendly thesaurus trusted by millions.
Discover accurate synonyms, antonyms, and definitions instantly while writing, editing, browsing, or studying online.
✔️ Key Features
• Instant Toolbar Search: Quickly find synonyms, antonyms, and definitions with one-click copy.
• On-page Results: Select any word on a page to instantly see synonyms and definitions. Ideal for editing directly in emails, documents, and text fields.
• Context Menu Shortcut: Access the full resources of PowerThesaurus.org by right-clicking any word on any page.
✨ PRO Membership Benefits
• Enjoy infinite scrolling for seamless browsing of extensive language resources.
• Customize your search experience with lists that prioritize the terms you use most.
• Use exclusive filtering options to refine results by part of speech.
⚙️ Configurable settings
• Quick Toggle: Easily enable or disable on-page tools using the toolbar icon for distraction-free writing.
• Flexible On-page Tools: Enable, disable, and customize how on-page results appear, including smart popup placement.
• Themes: Choose between system, dark, or light themes.
👍 Support & Feedback
• Love Power Thesaurus? Please rate us and leave a review! Your feedback helps us improve Power Thesaurus.
• Issues or suggestions? Please reach out to us at firefox@powerthesaurus.org.
🔒 Privacy Note
This extension processes only your search queries and account login data to provide synonyms, antonyms, definitions, and subscription features. It does not collect or share your personal browsing history.
Write with confidence using Power Thesaurus!
Discover accurate synonyms, antonyms, and definitions instantly while writing, editing, browsing, or studying online.
✔️ Key Features
• Instant Toolbar Search: Quickly find synonyms, antonyms, and definitions with one-click copy.
• On-page Results: Select any word on a page to instantly see synonyms and definitions. Ideal for editing directly in emails, documents, and text fields.
• Context Menu Shortcut: Access the full resources of PowerThesaurus.org by right-clicking any word on any page.
✨ PRO Membership Benefits
• Enjoy infinite scrolling for seamless browsing of extensive language resources.
• Customize your search experience with lists that prioritize the terms you use most.
• Use exclusive filtering options to refine results by part of speech.
⚙️ Configurable settings
• Quick Toggle: Easily enable or disable on-page tools using the toolbar icon for distraction-free writing.
• Flexible On-page Tools: Enable, disable, and customize how on-page results appear, including smart popup placement.
• Themes: Choose between system, dark, or light themes.
👍 Support & Feedback
• Love Power Thesaurus? Please rate us and leave a review! Your feedback helps us improve Power Thesaurus.
• Issues or suggestions? Please reach out to us at firefox@powerthesaurus.org.
🔒 Privacy Note
This extension processes only your search queries and account login data to provide synonyms, antonyms, definitions, and subscription features. It does not collect or share your personal browsing history.
Write with confidence using Power Thesaurus!
Rated 4.8 by 61 reviewers
Permissions and data
Required permissions:
- Input data to the clipboard
- Access your data for all websites
Optional permissions:
- Access your data for all websites
Required data collection, according to the developer:
- Search terms
Optional data collection, according to the developer:
- Technical and interaction data
More information
- Add-on Links
- Version
- 4.5.1
- Size
- 4.22 MB
- Last updated
- a month ago (Apr 10, 2026)
- Related Categories
- License
- Mozilla Public License 2.0
- Privacy Policy
- Read the privacy policy for this add-on
- Version History
- Tags
- Add to collection
The developer of this extension asks that you help support its continued development by making a small contribution.