Compare Grammarly and Diigo: Which Extension is the Best?

	Grammarly	Diigo
	Grammarly is a comprehensive writing assistant offering real-time grammar, spelling, punctuation, and style suggestions. With over 44 million users, it’s a trusted tool for enhancing your writing. Writing Education	Diigo is a handy tool for bookmarking, highlighting, and annotating web pages. It has many features, but its old design and limited highlight colors might make it less appealing. Highlighter Bookmark Manager
Key Features	Grammar Checker: Detects and corrects grammatical errors. Spelling Checker: Identifies and fixes spelling mistakes. Punctuation Checker: Ensures proper punctuation usage. Tone Detector: Analyzes the tone of your writing. Auto-Citations: Generates citations for online sources. Generative AI: Produces instant drafts, ideas, and replies.	Highlighting: Works well and highlights are recreated on refresh. Notes: You can add notes to your highlights. Link Creation: Create links to your highlights, although this feature is not very reliable. Sidebar Outliner: Simple design but requires time to understand. Syncing: Highlights are synced across devices.
Our Rating	8.8	7.8
Total users	54,568,609	200,000
Total ratings	47,132	2,319
Average rating	4.2 ⭐	4.6 ⭐
Entry Level Price	Free	Free
Chrome	4.5 42.8K+ ratings 39.0M+Users	4.6 2.3K+ ratings 200.0K+Users
Edge	3.9 1.1K+ ratings 14.9M+Users	-
Firefox	4.1 3.2K+ ratings 663.7K+Users	-
Safari	-	-
Features	9.5 Grammarly goes beyond basic grammar and spelling checks. It offers advanced features like tone detection, vocabulary enhancement, and generative AI capabilities. Compared to competitors, Grammarly provides a more comprehensive set of tools, making it a valuable asset for any writer.	8.5 Diigo offers basic features for a highlighter and bookmarking tool. It works well and we were able to highlight most websites and they were recreated when revisiting them. The highlighter popup makes it easy to highlight text offering 4 colors. It looks like this: We would have wished to have more color options. Also, note-taking and the tagging functionality are working, but its design does not look appealing. The dashboard where your highlights are stored works well and gives you an overview of all your highlights.
Performance	9.0 Grammarly performs well across different platforms, providing real-time suggestions without significant lag. The tool is reliable and helps improve writing efficiency.	8.0 Diigo performs well in terms of highlighting and syncing across devices. The fact that highlights are always synchronized can cause some loading delays. It's not as fast as other highlighters that use an offline-first approach, but it works reasonably well. However, the unreliable link creation feature and the simple sidebar outliner design need improvement.
Design	8.5 The design is clean and intuitive, making it easy to navigate. The color-coded underlines for suggestions are helpful, and the interface is user-friendly. However, some users might find the pop-ups slightly intrusive.	7.0 The design fulfills its functionality. The design of Diigo is outdated and could use a modern refresh. The lack of a nice overview of all your highlights on the page itself means you have to open the dashboard on diigo.com instead. The dashboard on diigo.com is okay, but other highlighters like Web Highlights have a much nicer user interface.
Value for Money	8.5 While Grammarly offers a free version, the Premium plan is relatively expensive. However, the advanced features and comprehensive feedback justify the cost for those who need a robust writing assistant. Grammarly is the priciest option for a reason—because, in our view, it's the best writing tool available in its category. If you're looking for the best writing assistant, go for the Premium plan, you won't regret it!	8.0 The free version of Diigo offers basic features and is fine for most users. The paid plans are reasonably priced and similar to other highlighters. However, we think other highlighters offer more value for the same price.
Ease of Use	9.0 Grammarly is straightforward to use, with a minimal learning curve. The browser extension integrates seamlessly with various platforms like Google Docs and Gmail, allowing you to get started right away.	7.8 Diigo is fairly easy to use, but the sidebar outliner takes some time to get used to. You can't see all your highlights on the page itself, so you have to go to the dashboard on diigo.com. We wish there was a sidebar to quickly access all our highlighted pages, like in the Web Highlights extension.
Security & Privacy	8.0 Grammarly takes privacy seriously, with stringent security measures in place. While an account is required, the company assures users that their data is not sold or made public. However, some users may still have concerns about data processing.	7.5 Diigo takes reasonable steps to protect user data. However, since you need an account and your data is stored in their database, absolute protection can't be guaranteed. We think a highlighter should work without needing to sign up, but this feature is missing in Diigo.
Conclusion	In our eyes, Grammarly is the best choice for anyone who wants to write professional articles or other things in English. Even though Grammarly has an expensice price tag, you can't get anything better on the market. We have been using Grammarly for a long time now. And even in the world of ChatGPT and other AI tools, Grammarly is just super handy and helpful. For us, the Premium plan is worth every penny. This only applies as long as you are in the English-speaking world. If you need other languages, we would recommend LanguageTool instead.	Diigo is a handy tool for collecting stuff from the web, like bookmarks, highlights, and notes. It’s a good deal with its premium plans, but the old-fashioned design and limited highlight colors might be a turn-off. If you want something that looks nicer and offers more customization, check out alternatives like Web Highlights.
	Install Grammarly	Install Diigo
Our Recommendation	In our comparison between Grammarly and Diigo, Grammarly came out on top, scoring 8.8. Grammarly is the most widely used, with over 55 million users and 47k+ reviews—and it also delivered the strongest performance in our tests. User reviews for Grammarly reflect our findings, while we rate Diigo lower than users do. Notably, Diigo has the highest user rating in the Chrome Web Store at 4.60, which is even higher than our rating of 7.8. There are some noticeable differences between these extensions, so it's worth considering your priorities and the details below. Looking for the richest feature set? Grammarly stands out with a rating of 9.5. On the other hand, Diigo lags behind in this area with a rating of 8.5. Need top performance? Grammarly stands out with a rating of 9. On the other hand, Diigo lags behind in this area with a rating of 8. Design lovers, take note: Grammarly stands out with a rating of 8.5. On the other hand, Diigo lags behind in this area with a rating of 7. Want to get the most for your money? Grammarly stands out with a rating of 8.5. On the other hand, Diigo lags behind in this area with a rating of 8. If you hate complicated tools, Grammarly stands out with a rating of 9. On the other hand, Diigo lags behind in this area with a rating of 7.8. With privacy and security becoming ever more important, Grammarly stands out with a rating of 8. On the other hand, Diigo lags behind in this area with a rating of 7.5. If you want a quick recommendation, Grammarly is our top pick. But as always, the best choice depends on what matters most to you.