Ultra Zoom vs. Thumbnail Zoom Plus
Thumbnail Zoom Plus (TZP) was the hover-zoom extension Firefox users swore by — until Firefox retired the legacy add-on system and most TZP forks went dark. Ultra Zoom is the modern replacement: same workflow, current platform, same codebase running on Chrome and Firefox alike.
Why TZP users are switching
- Built on the current add-on platform. Native WebExtensions / Manifest V3 — no XUL, no XPCOM, no waiting for a fork that won’t come. Read about the V3 trap.
- Active development. Releases every few weeks with new site plugins, not the years-long silence TZP users got used to.
- Same workflow, more sites. Reddit, Imgur, Tumblr, Twitter/X, Bluesky, Pinterest, Unsplash, Pexels, Wikimedia, Bilibili, Avito — first-class plugins on day one.
- Zero telemetry by design. No analytics endpoint, no remote code, no server that sees your browsing. Read the architecture.
Feature parity at a glance
| Feature | Thumbnail Zoom Plus | Ultra Zoom |
|---|---|---|
| Hover-to-zoom on every site | ✓ | ✓ |
| Site-specific page handlers | ✓ | ✓ |
| Works on current Firefox | No (legacy add-on) | ✓ |
| Works on Chrome / Edge / Brave | No | ✓ |
| Theater mode (Z) | – | ✓ |
| Gallery navigation (arrow keys) | ✓ | ✓ |
| Reverse image search shortcuts | Partial | ✓ |
| On-device AI upscaling | – | ✓ (Pro) |
| Active release cadence | Dormant | Every few weeks |
| Zero telemetry guarantee | Unclear | ✓ |
Coming over from Thumbnail Zoom Plus
- Install Ultra Zoom from the Firefox Add-ons store — signed and reviewed.
- If you still have a TZP fork installed, disable it — running both at once will fight over the hover overlay.
- Familiar shortcuts: hover to preview, arrow keys to navigate galleries, Z for theater mode, Esc to dismiss.
Try it free
The core extension is free forever, with the entire site catalogue. Pro is a 7-day free trial when you’re ready — see plans.