Best Email Tracker for Firefox in 2026
You just switched to Firefox - or you've been on it for years - and the email tracker you relied on doesn't have a Firefox extension. Mailsuite? Nope. Hunter MailTracker? Chrome-first. HubSpot Sales Extension? Not available on Firefox. Finding a solid email tracker for Firefox shouldn't require this much digging, but the ecosystem is genuinely thin compared to Chrome's.
We reviewed every Firefox email tracking extension we could find on AMO and dug through Reddit threads and community forums so you don't have to. Here's what works, what doesn't, and why open tracking alone isn't worth obsessing over.
Our Picks (TL;DR)
| Tool | Best For | Price | Firefox? |
|---|---|---|---|
| Boomerang | All-around tracking | Free-$49.98/mo | ✅ Yes |
| Prospeo | Verifying emails before tracking | Free-$39/mo+ | Chrome ext. |
| RightInbox | Gmail productivity suite | Free-$14.95/mo | ✅ Yes |
Boomerang is the safest bet for open and click tracking on Firefox. Prospeo solves the step most people skip - making sure the email address is valid before you bother tracking anything. RightInbox rounds it out if you want scheduling, reminders, and templates bundled in.
Top Firefox Email Trackers Compared
| Tool | Price | Firefox | Key Feature | Trust Signal |
|---|---|---|---|---|
| Boomerang | Free-$49.98/mo | ✅ | Open + click tracking | Multi-browser, proven |
| Prospeo | Free (75 emails/mo) | Chrome ext. | Email verification | 15,000+ companies, 98% accuracy |
| RightInbox | Free-$14.95/mo | ✅ | Gmail suite + tracking | Firefox install page |
| KJS Email Tracker | Free | ✅ | Proxy prefetch filtering | v1.0, zero ratings |
| Mail Tracker for Firefox | Free | ✅ | Pixel tracking | v1.0, zero ratings |
| Email Tracker for Firefox | Free | ✅ | Pixel injection | v1.0, zero ratings |
Boomerang
Use this if you want a proven, multi-browser email tracker with open and click tracking that's been around long enough to trust with your Gmail credentials. Boomerang's download page explicitly lists Firefox alongside Chrome, Safari, Edge, and Opera - no guessing required.
What makes Boomerang unusual is its privacy-forward approach. The tracking image is visible to recipients, and they can opt out. That sounds like a downside, but it actually builds trust with prospects who notice tracking pixels - and more of them do than you'd expect. We've seen recipients call out invisible pixels in reply-all threads. It's not a great look.
Pricing runs from free (10 message credits/month) through Personal at $4.98/mo up to Premium at $49.98/mo billed annually. The free tier is tight, but it's enough to test whether open tracking adds real value to your workflow before you commit money. If you're sending fewer than 10 tracked emails a month, the free plan honestly covers it.
Skip this if you need unlimited tracking on a free plan or you're sending high-volume outbound. Boomerang is built for individual productivity, not campaign-scale tracking.
Prospeo
Use this if you want to make sure your tracked emails actually arrive. Tracking opens on bounced or invalid emails is completely pointless - you're just watching zeros tick up on a dashboard.
The platform covers 143M+ verified emails with 98% accuracy, built on a proprietary 5-step verification process that includes catch-all handling, spam-trap removal, and honeypot filtering. The free tier gives you 75 verified emails per month, and paid plans start at $39/mo. For outbound teams, the workflow is straightforward: verify your list in Prospeo, then send tracked emails through your sequencer with Boomerang or another tracker handling the pixel.
The Chrome extension (40,000+ users) lets you find and verify contacts from any website or professional profile in one click. Pair it with Boomerang on Firefox for a complete stack: verify the address, then track the open. If you want to go deeper on verification-first workflows, see our guide to email deliverability.
RightInbox
RightInbox has a dedicated Firefox install page, which is more than most competitors can say. It bundles email tracking with scheduling, reminders, templates, and other Gmail productivity features in a single extension.
The free tier gives you 5 tracked emails per month. Paid plans include Personal at $7.95/month and Professional at $14.95/month, both billed annually, with separate Teams pricing also available.
Here's the trade-off: RightInbox isn't a pure tracking tool. It's a Gmail productivity suite that happens to include open tracking. That's a strength if you want fewer extensions cluttering your browser, but you'd be paying for features you might never touch if all you need is tracking.
KJS Email Tracker
This is the most technically interesting AMO-native option. KJS Email Tracker uses a Cloudflare Worker + KV backend and claims it filters out Gmail's image proxy prefetch - the automated requests that inflate open counts and create false positives. It also offers CSV export of tracking data and automatic reinjection of removed tracking pixels.
The catch: it's v1.0 with zero ratings on AMO. The proxy prefetch filtering idea is genuinely clever, but it's not something to bet your pipeline on today. If you're technical enough to evaluate the code and comfortable being an early adopter, it's worth a look. Everyone else should wait.
Other AMO Options
Mail Tracker for Firefox claims Gmail integration and real-time tracking using invisible tracking pixels. It's v1.0 with zero ratings, and its AMO listing shows it communicates with an external Railway app domain - adding a dependency most people won't want.
Email Tracker for Firefox is another v1.0, zero-rating option describing standard pixel tracking (1x1 invisible pixel injection) with real-time notifications and a simple dashboard. There's also Mailtrack for Gmail PM, a self-hosted option that requires you to run your own tracking server and requests "Access your data for all websites" permissions.
Let's be honest: installing any of these means you're beta-testing someone's side project with your Gmail credentials. Check the permissions carefully. If that makes you uncomfortable, stick with Boomerang.
Firefox email trackers show you who opened your message. But if 15-30% of your list bounces, you're tracking nothing. Prospeo verifies emails at 98% accuracy with a 5-step process that catches spam traps, honeypots, and catch-all domains - so every tracked send actually lands.
Stop tracking bounces. Verify 75 emails free every month.
Trackers That Don't Work on Firefox
Before you waste time searching:
- Mailsuite (formerly Mailtrack) - No Firefox extension. Rated 4.5/5 on Capterra with 227 reviews, but none of that matters if you're on Firefox.
- Hunter MailTracker - Chrome-first. The pricing page references Chrome notifications and "Install for Chrome" throughout. Free tier tracks 20 emails/month; paid plans start at $20/user/month billed annually. If you're comparing options, our breakdown of Hunter alternatives is a good starting point.
- HubSpot Sales Extension - Not available on Firefox per HubSpot's own community threads. HubSpot Sales Hub includes free tools for up to 5 users, with Starter at EUR15/month/seat.
Three of the most popular email trackers on the market don't support Firefox. That's frustrating, but it's the reality. You'll get better results choosing a tool that explicitly supports Firefox instead of trying to force a Chrome-centric tracker into your workflow.
Why Open Tracking Is Unreliable
Even with the perfect Firefox tracker installed, open rates aren't what they used to be. Apple Mail Privacy Protection masks IP addresses and generates machine opens, making open data noisy for a significant chunk of recipients. In our experience, open rates from Apple Mail users are essentially random numbers. Twilio's research found that 77% of marketers incorrectly believe MPP activates automatically - it actually requires user opt-in, meaning adoption is uneven and unpredictable across your recipient list.
On top of MPP, Gmail's own image proxy behavior can trigger false opens, and any recipient with images blocked won't register an open at all. Opens are a directional signal at best. Not ground truth. If you want the technical deep dive, see our guide to the email tracking pixel.
Track What Actually Matters
Here's the thing: if your outbound volume is under 500 emails a month, you probably don't need a dedicated open tracker at all. Clicks and replies tell you everything that matters. If someone clicks a link in your email, they engaged. If they reply, you've got a conversation. Those are the metrics worth optimizing around. (If you want to benchmark clicks properly, use our click rate formula.)
But the biggest lever isn't which pixel tracker you install - it's whether you're emailing the right person at a valid address. A 98% verified list with basic click tracking will outperform a dirty list with the fanciest open-tracking dashboard every single time. One of our customers, Stack Optimize, built to $1M ARR while maintaining deliverability above 94% and bounce rates under 3% - and that started with clean data, not better tracking pixels. If you're troubleshooting bounces, start with email bounce rate and then tighten your process with how to check if an email will bounce.
The best Firefox tracking setup pairs Boomerang's open tracking with Prospeo's verified contact data. 143M+ emails, 98% accuracy, and a 7-day refresh cycle mean you're never sending to stale addresses. At $0.01 per email, cleaning your list costs less than a single bounce costs your domain reputation.
Verify first, track second. Your domain reputation depends on it.
FAQ
Does Mailsuite work on Firefox?
No. Mailsuite doesn't have a Firefox extension as of 2026. For open tracking on Firefox, Boomerang and RightInbox are your best established options, with a handful of newer AMO add-ons available for the adventurous.
Are AMO email tracker extensions safe?
Most Firefox-native email trackers on AMO are v1.0 with zero user ratings and require access to your Gmail account plus external servers. Check the permissions list before installing - if you're uncomfortable giving an unproven extension inbox access, stick with Boomerang, which has a multi-year track record across browsers.
What's more reliable than open tracking?
Click tracking and reply rates give you far more accurate engagement signals than pixel-based open tracking. Opens are inflated by Apple Mail Privacy Protection and Gmail's image proxy, making them unreliable as a primary metric. For even better results, verify your email list before sending - catching invalid addresses at 98% accuracy means your tracking data reflects real engagement instead of bounces.