Firefox Browser Add-ons
  • Extensions
  • Themes
    • for Firefox
    • Dictionaries & Language Packs
Log in
Preview of Sessyn

Sessyn by Aegyrix, LLC

Tracker blocker, cookie inspector & offline location spoofer. Blocks analytics, ad & session-recording trackers while keeping logins & payments intact. Declines cookie banners, syncs time zone, sends GPC, and never sees your browsing.

Available on Firefox for Android™Available on Firefox for Android™
0 (0 reviews)0 (0 reviews)
Download Firefox and get the extension
Download file
Scan the QR code to open this extension in Firefox for Android

Extension Metadata

Screenshots
About this extension
Sessyn blocks tracking without breaking the sites you use.

• Blocks known analytics, advertising and session-recording trackers, using rules that each cite the tracker's own published documentation.
• Leaves sign-in, payments and site security alone.
• Private mode strips cross-site cookies; Lockdown also restricts third parties it cannot identify. If a site breaks, one click pauses it for that site.
• Sends the Global Privacy Control (GPC) signal and strips click-tracking URL parameters.
• Shows what it did on each page and which companies were involved.
• Cookie Inspector & Library: see a site's cookies grouped by purpose (sign-in and security, site settings, analytics and advertising), each with the primary source that names it, plus when each cookie and login expires.
• Explain This Cookie: for any cookie, what it stores on your device, what it is for, and what the site's server could link to it.
• Export a site's cookies as JSON, cookies.txt or an HTTP header on your device, only when you ask. Values are never stored or sent.
• Forget This Site clears a site's cookies and storage in one step.
• Optional: detect canvas, WebGL, audio and navigator fingerprinting, and automatically decline common cookie consent banners (OneTrust, Cookiebot, IAB TCF, Didomi, iubenda, Klaro, CookieConsent), never overriding a choice you made.
• Optional: 100% offline Location & Time Zone Spoofer — give sites that ask for your location any place you choose on a built-in cartographic vector map (135,000+ cities, towns and airports, highways, railways and national parks) or paste coordinates, with automatic browser time zone matching. The map ships inside the extension, so where you look is never sent anywhere.
• Optional: keep an on-device tally of the companies behind what Sessyn did on the pages you check. Counts only, never sites, never sent.

Built to be accessible (Desktop & Firefox for Android)
• 7 themes including Dark, Light, High Contrast, Color-Blind Safe and Easy Reading, or Match My System to follow your device.
• Text size, reduced motion, stronger focus outlines and underlined links.
• Works by keyboard, touch and screen readers across Firefox Desktop and Firefox for Android.

Private by design
• Blocking is done by the browser's built-in declarative rule engine, so Sessyn never sees the requests it blocks.
• On its own, Sessyn makes one kind of request: a periodic check for updated tracker rules and cookie descriptions. It carries no identifier, and every update is cryptographically signed and verified before use.
• No account, no analytics, no ads, no third-party code.
• Permissions beyond the basics are asked for only when you turn on the feature that needs them, and can be revoked.

Help improve the rules (optional)
Nothing about your browsing leaves your device unless you choose to send a report, and you see exactly what it contains first. A report lists the sites you captured, the third-party hosts they loaded and cookie names: never cookie values, page addresses or content. Sessyn keeps it 30 days, and you can delete it from the popup at any time.

Privacy policy: https://sessyn.com/privacy/
Rated 0 by 0 reviewers
Log in to rate this extension
There are no ratings yet

Star rating saved

5
0
4
0
3
0
2
0
1
0
No reviews yet
Permissions and data

Required permissions:

  • Block content on any page

Optional permissions:

  • Clear recent browsing history, cookies, and related data

Data collection:

  • The developer says this extension doesn't require data collection.

Optional data collection, according to the developer:

  • Browsing activity
  • Technical and interaction data
Learn more
More information
Add-on Links
  • Homepage
  • Support site
  • Support Email
  • Copy add-on ID
Version
1.0.8
Size
10.87 MB
Last updated
13 hours ago (Nov 12, 2026)
Related Categories
  • Web Development
  • Privacy & Security
License
Mozilla Public License 2.0
Privacy Policy
Read the privacy policy for this add-on
Version History
  • See all versions
Tags
  • ad blocker
  • anti tracker
  • content blocker
  • dark mode
  • privacy
  • security
Add to collection
Report this add-on
Go to Mozilla's homepage

Add-ons

  • About
  • Firefox Add-ons Blog
  • Extension Workshop
  • Developer Hub
  • Developer Policies
  • Community Blog
  • Forum
  • Report a bug
  • Review Guide

Download

  • Download Firefox
  • Windows
  • macOS
  • iOS
  • Android
  • Linux
  • All

Latest Builds

  • Nightly
  • Beta

Firefox for Business

  • Enterprise

Community

  • Connect
  • Contribute
  • Developer

Follow

  • Instagram
  • YouTube
  • TikTok
  • Bluesky
  • Podcast
  • Privacy
  • Cookies
  • Legal

Except where otherwise noted, content on this site is licensed under the Creative Commons Attribution Share-Alike License v3.0 or any later version. Android is a trademark of Google LLC.