AdBlock for Firefox vs AdBlocker Ultimate: Which Is Safer?
At a glance: verified facts
| Fact | AdBlock for Firefox | AdBlocker Ultimate |
|---|---|---|
| Published by | AdBlock | AdAvoid |
| Publisher public | Yes | Yes |
| Policy changes we track | None detected | None detected |
| Last data check | 2026-06-18 | 2026-06-18 |
From public records (the extension's store listing, publisher registry, manifest metadata) and our policy snapshots — a "—" means we have no verified data for that field yet.
What the evidence shows
Both are ad & content blockers extensions we track. Comparing the 4 safety dimensions measured for both:
- On publisher & identity, the two are evenly matched (60% vs 60%).
- On permissions & access, the two are evenly matched (85% vs 85%).
- On maintenance & ownership, the two are evenly matched (100% vs 100%).
- AdBlocker Ultimate leads on community reputation (100% vs 92%).
Not yet measured for either extension: Data & Privacy — this comparison covers only what we verified.
Safety score breakdown
| Dimension | AdBlock for Firefox | AdBlocker Ultimate |
|---|---|---|
| Publisher & Identity | 4.8/8 | 4.8/8 |
| Permissions & Access | 14.17/16.67 | 14.17/16.67 |
| Data & Privacy | — | — |
| Maintenance & Ownership | 7.5/7.5 | 7.5/7.5 |
| Community Reputation | 9.15/10 | 10/10 |
| Total | 84.47/100 | 86.48/100 |
Frequently asked questions
Is AdBlock for Firefox safer than AdBlocker Ultimate?
AdBlocker Ultimate currently scores higher — 86/100 vs 84/100 — across the 4 safety dimensions measured for both. That covers documented evidence only, not features or pricing.
Is AdBlock for Firefox safe?
AdBlock for Firefox currently holds safety grade A (84/100) based on 4 of 5 safety dimensions, and is published by AdBlock. The grade reflects only what we have measured; anything not yet assessed is marked as pending on the full report.
Is AdBlocker Ultimate safe?
AdBlocker Ultimate currently holds safety grade A (86/100) based on 4 of 5 safety dimensions, and is published by AdAvoid. The grade reflects only what we have measured; anything not yet assessed is marked as pending on the full report.
More Ad & Content Blockers extension comparisons
How this comparison works
Both extensions are scored with the same five-dimension, 100-point rubric — publisher & identity, permissions & access, data & privacy, maintenance & ownership and community reputation — using documented evidence only; a dimension with no evidence stays unscored instead of guessed. Read the full reports: AdBlock for Firefox safety report · AdBlocker Ultimate safety report, or run any other extension through the safety check.