Compare Diigo and Merlin AI: Which Extension is the Best?
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. | ||
| Key Features A summary of the most important features offered by each extension. |
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| Our Rating Tooltivity's expert review score for each extension, based on hands-on testing and research. | 7.8 | 8.4 Winner in this category |
| Total users Total active users across all major browsers: Chrome, Edge, Firefox, and Safari. | 200,000 | 1,000,000 Winner in this category |
| Total ratings Total number of user ratings received across all supported browsers. | 2,319 | 8,802 Winner in this category |
| Average rating Average user rating across all browsers, calculated from available store ratings. | 4.6 ⭐ | 4.8 ⭐ Winner in this category |
| Entry Level Price The minimum price required to start using the extension. "Free" means a free tier is available. | Free | Free |
| Chrome User rating and stats for the extension on Chrome browser. |  4.6 3.56 Average Chrome Web Store rating from the last 100 reviews 200.0K+Users | 4.8 3.24 Average Chrome Web Store rating from the last 100 reviews 1.0M+Users Winner in this category |
| Edge User rating and stats for the extension on Edge browser. | - | - |
| Firefox User rating and stats for the extension on Firefox browser. | - | - |
| Safari User rating and stats for the extension on Safari browser. | - | - |
| Features Tooltivity's expert score for the 'Features' aspect of each extension. | 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.  Winner in this category | 8.0 Merlin AI offers a variety of features including summarizing, writing, coding, diagramming and more. It supports multiple AI models such as GPT-4, Claude and Gemini and allows users to create custom AI chatbots and knowledge bases. The platform also integrates with the web and files in real time. However, some features, such as PDF summarization, are not as robust as those of specialized tools. It also lacks what we consider to be the important function of direct communication between AI and the current website. In addition, the function of direct communication between AI and the current website, which we consider important, is missing.  |
| Performance Tooltivity's expert score for the 'Performance' aspect of each extension. | 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. Winner in this category | 7.5 Merlin is generally fast and responsive, but it can slow down browsers, especially on older hardware. There are occasional bugs and crashes, though the team releases frequent updates and improvements. |
| Design Tooltivity's expert score for the 'Design' aspect of each extension. | 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. | 9.1 The design has a modern look and feel, with handy keyboard shortcuts and sidebar integration that make navigation easier. That said, the user interface can feel cluttered and overwhelming, especially for new users, and there are inconsistencies between the extension, web, and mobile versions.  Winner in this category |
| Value for Money Tooltivity's expert score for the 'Value for Money' aspect of each extension. | 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. | 8.2 The free plan is generous for light users, offering a substantial daily quota and access to a wide range of basic features. The Pro plan is competitively priced, especially when compared to the cost of subscribing to multiple separate AI tools, and unlocks unlimited access to all models and advanced features. However, the absence of a free trial for premium features means users must commit before experiencing the full capabilities of Merlin AI. Additionally, some users report that the query system—where different models and features consume varying amounts of daily queries—can be confusing or feel restrictive, particularly for those trying to understand how far their usage will go on each plan. Winner in this category |
| Ease of Use Tooltivity's expert score for the 'Ease of Use' aspect of each extension. | 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. | 8.5 Getting started with Merlin AI is straightforward—installation is quick, and the onboarding process is simple enough for most users to begin using core features right away. However, the platform’s extensive feature set can be overwhelming at first, leading to a noticeable learning curve as users explore everything it offers. Some users have expressed confusion about how the daily query limits work, how different models are selected or switched, and which features are available on each plan. Occasional bugs and log-in issues can also disrupt the workflow, requiring users to troubleshoot or reach out to support. Overall, while Merlin AI is accessible, mastering its full capabilities may take some time and patience, especially for those new to AI tools. Winner in this category |
| Security & Privacy Tooltivity's expert score for the 'Security & Privacy' aspect of each extension. | 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. | 9.3 Merlin does not sell user data to third parties and only uses data for core functionality. The privacy policy is transparent, but some users remain concerned about the amount of data collected and the permissions required. Winner in this category |
| Conclusion A summary of our findings and final thoughts for each extension. | Diigo is a handy tool for collecting stuff from the web, like bookmarks, highlights, and notes.
| Merlin AI is a powerful and versatile tool that can really boost the productivity of a wide range of users. The integration of multiple AI models and functions into a single extension is ideal for this p However, Merlin is not completely perfect. We encountered occasional bugs, inconsistencies in the user interface and some performance issues. Pricing can also be confusing, and some features are locked behind a paywall.. Overall, Merlin AI is a good choice for anyone looking for an all-in-one AI assistant for the browser - especially if you value having multiple AI models and tools in one place. |
| Our Recommendation | In our comparison between Diigo and Merlin AI, Merlin AI came out on top, scoring 8.4. Merlin AI is the most widely used, with over 1 million users and 9k+ reviews—and it also delivered the strongest performance in our tests. We rate Diigo and Merlin AI lower than users do. Notably, Merlin AI has the highest user rating in the Chrome Web Store at 4.80, which is even higher than our rating of 8.4. There are some noticeable differences between these extensions, so it's worth considering your priorities and the details below.
If you want a quick recommendation, Merlin AI is our top pick. But as always, the best choice depends on what matters most to you. | |
