PixelBlock vs Gblock: Which Blocks More Email Tracking?

If you want to stop senders from seeing when you open their email, you have probably narrowed it down to PixelBlock vs Gblock. PixelBlock is the long running, free favorite that flags open tracking pixels with a red eye icon. Gblock is the newer option that blocks pixels and the tracked links inside a message, on a blocklist that updates itself. Both are legitimate tools, and this comparison gives PixelBlock full credit while being clear about where the two genuinely differ, so you can pick the email tracker blocker that fits how you use Gmail.

Here is the quick verdict before the detail. If you are after a free, set and forget way to stop read receipts in Chrome, PixelBlock is a fine choice and a good PixelBlock alternative is overkill. If you want to also block the tracked links that log your clicks, run on Edge, Brave, or Arc, and lean on a blocklist that refreshes itself rather than aging in place, Gblock is the stronger fit. The rest of this PixelBlock review walks through exactly why, feature by feature, so the decision is yours and not ours.

Key Takeaways

• PixelBlock is free and blocks email open tracking pixels in Gmail, showing a red eye icon next to the sender when it catches one.
• Gblock blocks open pixels and also strips tracked, rewritten links, so a click cannot be logged through a redirect.
• PixelBlock leans on a largely static list, while Gblock auto updates its blocklist and detects new tracking patterns as they appear.
• PixelBlock runs on Chrome and other Chromium browsers; Gblock supports Chrome, Edge, Brave, and Arc.
• PixelBlock is free; Gblock is a paid tool with a free 30 day trial and no credit card required to start.

What Is PixelBlock?

PixelBlock is a free Chrome extension that blocks email open tracking pixels inside Gmail. It has been around for years and earned a reputation as the simple, no fuss choice for people who just want to stop read receipts. Install it, open Gmail, and it works with no setup. When a message carries a tracking pixel, PixelBlock keeps the pixel from loading and places a small red eye icon next to the sender's name so you can see, at a glance, that someone tried to track the open.

There is a lot to like here, and any fair PixelBlock review has to say so. It is genuinely free, it runs locally in your browser so no email data leaves your device, and the red eye indicator is a clean, honest piece of feedback that most blockers do not bother to show. For a single goal, blocking the open pixel, PixelBlock does the job and asks nothing in return.

The limits are worth naming too. PixelBlock focuses on open pixels, not the tracked links inside an email. It runs on Chrome and other Chromium browsers tied to Gmail, and its detection has historically relied on a list that does not change very often. It did migrate to Chrome's newer Manifest V3 in a late 2025 update, which resolved a long stretch where some users reported it had stopped working, but the underlying model is still a relatively fixed list rather than one that refreshes on its own.

Why does that update cadence matter? Tracking is not static. Senders rotate the domains that host their pixels, and tools like GMass openly publish techniques for slipping past pixel blockers, including offering custom tracking domains so the pixel does not sit on an obvious, easy to block address. A blocker that catches last year's domains beautifully can still miss the one that launched last month. PixelBlock is excellent at the job it was built for, and for many people that job, stopping the plain open pixel, is enough. The question is simply whether you want coverage that also keeps pace with new trackers and reaches the link layer, and that is where the comparison gets interesting.

What Does Gblock Do Differently?

Gblock blocks the same open pixels PixelBlock does, then goes after the parts PixelBlock leaves alone. The clearest difference is scope: Gblock strips tracked, rewritten links so a click is not quietly logged through a redirect, where PixelBlock stops at the open pixel. Trackers increasingly measure clicks, not just opens, so closing that second channel matters.

The second difference is freshness. Gblock's blocklist updates automatically and its detection engine flags new tracking patterns as they show up, rather than waiting for a manual list refresh. That auto updating model is the real reason to consider it as a PixelBlock alternative, because trackers add new domains constantly and a list from last year falls behind. Gblock currently recognizes tens of thousands of known trackers and adds more on an ongoing basis.

There is also a difference in feedback. PixelBlock's red eye icon is a nice touch that tells you a tracker was caught on that message; Gblock takes the quieter route and simply blocks in the background, which some people prefer and others miss. Neither approach is wrong. It comes down to whether you want a visible nudge each time or a clean inbox that just does not report on you. Both run inside Gmail with no per email fiddling once installed.

Beyond that, the two are similar in spirit. Gblock supports a wider set of browsers: Chrome, Edge, Brave, and Arc, so it follows you if you have left Chrome behind. The honest trade off is price. Gblock is a paid product, where PixelBlock is free, though Gblock offers a free 30 day trial with no card required so you can test it against your real inbox first. That trial is the fairest way to settle the comparison for yourself: run it for a few weeks, watch what it strips that a pixel only blocker would have let through, and decide whether the extra coverage is worth it for your inbox.

PixelBlock vs Gblock: Side by Side

The short version: PixelBlock wins on price and simplicity, Gblock wins on coverage and freshness. Here is how the two stack up across the things buyers actually weigh.

Which Should You Choose?

Choose PixelBlock if you want a free, simple tool that stops open pixels and shows you when it does. If your only worry is read receipts, you are on Chrome, and you like the red eye confirmation, PixelBlock is a solid, honest pick that costs nothing. There is no shame in starting there.

Choose Gblock if you want broader coverage that keeps up over time. The two reasons to pay are concrete: it strips tracked links as well as pixels, so click logging stops too, and its blocklist updates itself instead of aging in place. If you live in your inbox, get a lot of sales and marketing mail, or use Edge, Brave, or Arc, that extra coverage and the auto updating list are what you are paying for. The 30 day trial lets you confirm it catches things on your own messages before you commit.

It is also fine to use the comparison as a sequence rather than a fork in the road. Plenty of people start with PixelBlock because it is free, get comfortable with the idea that blocking trackers does not break their email, and only move to a paid PixelBlock alternative once they realize how much link tracking slips past a pixel only tool. There is no lock in either way, both are quick to install and remove, so trying the one that fits your situation today costs you nothing but a couple of minutes.

If you want to see how both stack up against the rest of the field, we compared the major options in the best email tracker blocker extensions and in our roundup of email tracker Chrome extensions and how to block them. For the broader fundamentals, see how to block email tracking in Gmail.

Source: PixelBlock on the Chrome Web Store.