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Cybersecurity · head to head

Avast One vs Mozilla Firefox

Avast One logo

Avast One

Cybersecurity

All-in-one protection for your digital life

From
Free
Rated
-
Full reviewWebsite
Mozilla Firefox logo

Mozilla Firefox

Technology

An independent web browser with its own rendering engine, funded almost entirely by search placement deals.

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Avast One ransomware and Wi-Fi vulnerability protection only on paid plans; Mozilla Firefox roughly 85 per cent of Mozilla's revenue comes from search default placement deals, overwhelmingly with Google, so the organisation that competes with Chrome depends on Chrome's owner for its funding and any renegotiation lands on Firefox's engineering budget within a quarter.
  • They diverge on capability: Avast One covers Antivirus, Mozilla Firefox covers Gecko engine.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Avast One and Mozilla Firefox actually diverge.

Attributes where Avast One and Mozilla Firefox differ
AttributeAvast OneMozilla Firefox
PlatformsWindows, macOS, iOS, AndroidWindows, macOS, Linux, iOS, Android
CategoryCybersecurityTechnology
Founded19882004

Identical on both: starting price (Free), pricing model (Unknown), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Avast One

  • Antivirus
  • Firewall
  • VPN
  • Data breach monitoring
  • Email Guardian
  • Webcam Shield
  • Ransomware Shield
  • Performance optimization

Only in Mozilla Firefox

  • Gecko engine
  • Full webRequest blocking
  • Total Cookie Protection
  • Container tabs
  • Extended Support Release
  • policies.json and ADMX
  • Built-in developer tools
  • Firefox Sync

What people use each for

The jobs each tool is most often brought in to do.

Avast One

  • Antivirusnot Mozilla Firefox
  • Internet Securitynot Mozilla Firefox
  • Privacy Toolsnot Mozilla Firefox

Mozilla Firefox

  • Web development where you need to test against a non-Chromium engine before shipping, because Chromium-only testing hides real bugsnot Avast One
  • Users who require a full-strength content blocker, which Chrome's Manifest V3 no longer permitsnot Avast One
  • Managed fleets that need a browser on a slow release cadence with Group Policy control, using the ESR channelnot Avast One
  • Handling several accounts on the same service at once through container tabs, without separate profiles or private windowsnot Avast One

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Avast One

  • Ransomware and Wi-Fi vulnerability protection only on paid plans
  • Free plan VPN is limited, no data breakthrough monitoring
  • Rebuilt app in May 2026 may have stability issues

Mozilla Firefox

  • Roughly 85 per cent of Mozilla's revenue comes from search default placement deals, overwhelmingly with Google, so the organisation that competes with Chrome depends on Chrome's owner for its funding and any renegotiation lands on Firefox's engineering budget within a quarter.
  • Desktop market share sits at a few per cent, so commercial sites are tested against Chrome and Safari and a Firefox-only rendering or WebRTC bug is triaged as low priority by the site owner, leaving you with the workaround.
  • On iOS and iPadOS the browser is a WebKit shell required by Apple's rules, so it delivers the interface and Sync but none of the engine, extension or tracking-protection behaviour that make Firefox worth choosing on desktop.
  • Mozilla declines to implement several hardware-facing APIs on principle, including WebUSB, WebSerial, Web Bluetooth and WebHID, so a web application that talks to a device simply does not run and no configuration flag changes that.
  • Enterprise management is limited to policies.json and ADMX templates; there is no first-party equivalent of Chrome Browser Cloud Management, so fleet-wide reporting on versions and extensions requires third-party tooling you have to buy or build.
  • Mozilla repeatedly ships decisions its own user base objects to, such as enabling Privacy Preserving Attribution by default and the 2025 Terms of Use rewrite, and reversals arrive after the news cycle, so deploying it on a privacy argument means owning the communications work each time.

Pricing, plan by plan

Avast One

Free
  • FreeFree
    • Antivirus
    • Limited VPN
    • Privacy tools
  • Silver$2.99/month
    • Enhanced antivirus
    • VPN
    • Device cleanup
  • Premium$4.19/month
    • Full antivirus
    • VPN with 55 servers
    • Password manager
  • Premium Plus$11.67/month
    • All Premium features
    • 30 devices covered

Mozilla Firefox

Free

No published plan breakdown. See the Mozilla Firefox review.

Which should you pick?

Choose Avast One if

  • You need antivirus.
  • You want to start without paying.
  • You work on Windows, macOS, iOS, Android.
  • You also want firewall.
Avast One review

Choose Mozilla Firefox if

  • You need gecko engine.
  • You want to start without paying.
  • You work on Windows, macOS, Linux, iOS, Android.
  • You also want full webrequest blocking.
Mozilla Firefox review

Questions people ask

Is Avast One or Mozilla Firefox better?
Neither clearly leads. Avast One starts at Free and Mozilla Firefox at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Avast One or Mozilla Firefox?
Avast One starts at Free and Mozilla Firefox at Free.
Does Avast One or Mozilla Firefox run on more platforms?
Avast One runs on Windows, macOS, iOS, Android. Mozilla Firefox runs on Windows, macOS, Linux, iOS, Android.
Can I use Avast One for free?
Both have a free tier, so you can try either at no cost before committing.
What is Avast One best used for?
Avast One is most often used for antivirus, internet security, privacy tools. Of those, antivirus and internet security are not what Mozilla Firefox is typically brought in for.
What can Avast One do that Mozilla Firefox cannot?
Avast One covers Antivirus, Firewall, VPN, Data breach monitoring. Mozilla Firefox covers Gecko engine, Full webRequest blocking, Total Cookie Protection, Container tabs.

Answered from the vendors’ own pages

Avast One: Is Avast One free?

Yes. Avast One offers a free tier with antivirus, VPN (limited), and privacy tools. Paid plans start at $2.99/month for Silver and $4.19/month for Premium covering up to 5 devices.

Source
Mozilla Firefox: Does uBlock Origin still work on Firefox?

Yes. Firefox has kept the blocking webRequest API that Chrome removed with Manifest V3, so uBlock Origin runs with its full rule set rather than the cut-down Lite version Chrome requires.

Avast One: What does Avast One include?

Avast One provides antivirus, VPN, password manager, device cleanup, Wi-Fi security, data breach monitoring, and protection against AI-generated scams and deepfakes.

Source
Mozilla Firefox: Is Firefox on iPhone the same browser?

No. Apple's platform rules require it to use WebKit, so on iOS and iPadOS you get Firefox's interface, Sync and bookmarks on top of Safari's engine. The privacy and extension behaviour are not the same.

Avast One: Does Avast One have ransomware protection?

Ransomware protection is available only on paid plans, not the free tier. Free users get antivirus and basic protection only.

Source
Mozilla Firefox: How is Mozilla funded, and does that matter?

Mainly by payments for making a search engine the default, with Google as the dominant payer. It matters because it is a single-source dependency on a direct competitor, and it has been the subject of antitrust litigation whose outcome Mozilla does not control.

Mozilla Firefox: Can I manage it across a company fleet?

Yes, through policies.json or Windows Group Policy with the ADMX templates, and the ESR channel gives you a roughly yearly major version instead of four-weekly. There is no first-party cloud management console, so reporting needs other tooling.

Mozilla Firefox: Will every site work in it?

Most will. The exceptions cluster around sites tested only in Chrome, legacy enterprise applications, and anything using WebUSB, WebSerial, Web Bluetooth or WebHID, which Firefox does not implement at all.

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