Email Tracking in Chrome, Brave and Arc

The extension is built for Chrome. In practice, most people who use it are not in Chrome.

Table of contents

Brave, Arc, Edge, Vivaldi and Opera are all built on Chromium and install Chrome extensions. They behave slightly differently, and those differences matter for a tool that lives inside your webmail.

Chrome

The reference case. The extension installs from the Chrome Web Store, injects itself into Gmail and Zoho Mail, and stores its key in the browser's synchronised storage, which means a second Chrome profile signed into the same Google account picks up the connection.

Brave

Brave installs Chrome extensions directly from the Chrome Web Store. The one thing to check is Brave Shields: aggressive blocking settings can interfere with third-party requests on a page. The extension talks to its own API, not to a tracker, so it is rarely blocked, but if the connection page seems to hang, lowering Shields on mailcheck.fr for one visit resolves it.

Note the asymmetry, which is worth knowing: Brave blocks tracking pixels for you as a recipient by default. If you send a tracked email to a Brave user reading in a browser, you may never see an open. That is not a bug in the tool, it is the recipient's software doing what it promises.

Arc

Arc is where most of the real-world questions come from, because of spaces. People organise their work by client or project, each space with its own set of tabs and often its own Google or Zoho account.

Extensions in Arc are installed once and available across spaces. The tracking toggle appears in whichever webmail you open, in whichever space. Since mailcheck ties tracking to your account rather than to a mailbox, sending from three different addresses in three different spaces produces one unified history.

Edge, Vivaldi, Opera

All three accept Chrome extensions, Edge through its own add-ons page or the Chrome Web Store with a one-time confirmation. Behaviour is otherwise identical. Edge users on a managed corporate device may find extension installation restricted by policy, which is an IT question rather than a technical one.

What does not work

Safari and Firefox do not run Chrome extensions. There is no workaround; those browsers require a separately built extension.

Mobile browsers do not support extensions either. Tracking is enabled when you compose in a desktop browser. Once sent, opens are recorded regardless of where the recipient reads the message, and you receive notifications wherever the browser is running.

Why the browser matters more than people expect

An email tracker that lives in an extension is unusual: it operates inside a page it does not own, in a browser that may be actively trying to limit what pages and extensions can do.

Three mechanisms interact. The extension needs permission to run on your webmail's domain. It needs to reach its own API from that page. And it needs somewhere to keep your credentials between sessions. Each browser handles those three slightly differently, which is why the same extension can feel flawless in one and temperamental in another.

The good news is that the differences are almost entirely about defaults rather than capability. Every Chromium browser can run the extension correctly once its blocking settings are understood.

Profiles, and the trap of the second install

Most people who work across several clients end up with several browser profiles, or several Arc spaces, each signed into a different account.

This is good practice and it used to break tracking tools in a specific way: connecting the extension in a second profile would invalidate the credentials of the first, silently. You would discover it days later, when a message you thought was tracked had recorded nothing.

In mailcheck this is fixed: connecting a new profile no longer revokes the key used by another, and a key that has been used is protected from cleanup. If you work in two profiles, connect both once, and both keep working.

What happens on the recipient's side

There is an asymmetry worth sitting with. The browser you use affects whether you can track. The browser and client your recipient uses affects whether tracking works at all.

• Brave and privacy-first browsers block many tracking requests by default, so a recipient reading your message there may never register an open.
• Apple Mail with Privacy Protection loads images through a proxy, producing opens that no human made.
• Corporate gateways fetch everything to scan it, often within seconds of delivery.

The share of recipients in one of those categories grows every year. This is the single best argument for treating open data as an aid to timing rather than as a measurement.

A quick diagnostic when nothing works

If the toggle does not appear in your compose window, work through this in order:

1. Confirm the extension is enabled for the profile you are actually in, not just installed somewhere.
2. Reload the webmail tab completely. Extensions inject on page load, and a long-lived tab may predate the install.
3. Check that you are on the web interface, not a desktop mail application. The extension lives in the browser.
4. If the toggle appears but refuses to switch on, your account is not connected or you have reached the monthly free limit. Both now display a message rather than failing silently.

Conclusion

If your browser is built on Chromium, the extension works, and the only real variable is how aggressively that browser blocks things by default. The more interesting consequence is on the receiving side: as privacy-first browsers and mail clients spread, open tracking becomes a weaker signal every year. Which is an argument for treating it as one input among several, not as a measurement.

Frequently asked questions

Does the extension work in Safari or Firefox?

No. Both require a separately built extension, and the mailcheck extension is built for Chromium browsers: Chrome, Brave, Arc, Edge, Vivaldi and Opera.

Will Brave block my own tracking?

Brave may interfere with the connection page if Shields are aggressive, which is resolved by lowering them once for that page. More importantly, a recipient reading in Brave may never register an open, since it blocks tracking requests by default.

Can I use it in two browser profiles at once?

Yes. Connecting a second profile no longer invalidates the first, and both report into the same account and the same history.

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