Compare Voila, Grammarly, Sider, and Merlin AI: Which Extension is the Best?

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.

Grammarly performs well across different platforms, providing real-time suggestions without significant lag. The tool is reliable and helps improve writing efficiency.

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.

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.

The design of Sider is very user-friendly, and the interface is quite clear, so it's easy to find anything. The sidebar is great because you can access features without leaving the page. However, it might feel cluttered for some people as there are so many options. A sleeker design could improve the user experience.

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.

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!

While Sider offers a free version with limited requirements, the premium plans can be expensive for casual users. While the feature set justifies the cost for power users, those who only need basic features may find it expensive. The availability of different pricing tiers offers flexibility, but an intermediate solution with a cheaper option could appeal to a wider audience.

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.

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.

In our tests, Sider was easy to use without having to learn how to use it. The tooltips and instructions help you get started right away. It works well in our tests with popular browsers such as Chrome and Edge, which are quick to install and use. However, if you want to delve into the advanced functions, it can take a while to get to grips with everything. Basic users might be a little overwhelmed here.

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.

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.

Sider stores the data on Amazon's US servers. The data protection guidelines are transparent and users have control over their data. However, usage data is collected for analysis purposes, which not every user will find acceptable. The assurance that data is never passed on and no spam messages are sent is a positive aspect.