What icon sizes does a Firefox add-on need?

Firefox add-ons should include icons at 16×16, 32×32, 48×48, 96×96, and 128×128 pixels. The 128px icon is used for the AMO (addons.mozilla.org) listing.

What format should Firefox add-on icons be?

Firefox add-on icons must be PNG format. SVG is also supported for browser action and page action icons in the manifest. PNG with transparency is recommended for toolbar icons.

Where do I reference icons in a Firefox extension?

Reference your icons in manifest.json under the 'icons' key for general extension icons, and under 'browser_action.default_icon' for the toolbar icon.

Are my images uploaded to a server?

No. All processing happens entirely in your browser using the Canvas API. Your images never leave your device.

Does Firefox require a different icon than Chrome for extensions?

The manifest icon sizes are similar (16, 32, 48, 128px), but Firefox additionally benefits from a 96×96 icon for high-DPI (Retina) displays. Chrome handles Retina scaling differently, so 96px is a Firefox-specific best practice.

What is the AMO review process for Firefox add-on icons?

Mozilla's AMO review team checks that your icon is clearly related to your add-on's functionality and complies with Mozilla's content guidelines. Icons must not use trademarks or branding of other companies without permission. Human review typically occurs within a few days of submission.

Firefox Add-on Icon Generator — Resize Icons for Firefox

Why Use This Tool?

Firefox (via Mozilla) is still a widely used browser among developers, privacy-conscious users, and enterprise environments. Publishing on addons.mozilla.org (AMO) requires icons at multiple sizes. Unlike Chrome, Firefox specifically benefits from the 96px size for high-DPI (Retina) displays where 48px icons would otherwise appear blurry.

Firefox Add-on Icon Size Guide (2026)

Usage	Size (pixels)	Notes
AMO Store Listing	128×128	Main store icon
Add-on Manager	48×48	Shown in browser extension list
Retina Toolbar	96×96	High-DPI (2× of 48px)
Context Menu	32×32	Small UI contexts
Smallest Icon	16×16	Favicon-size contexts

Privacy First — 100% Client-Side

Your images are processed entirely in your browser using the HTML5 Canvas API. Nothing is uploaded to any server. You can verify this by disconnecting from the internet after loading the page — the tool works offline.

Tip: Firefox uses both the 48×48 and 96×96 icons — 48px for standard displays and 96px for high-DPI (Retina) displays. If you only supply 48px, Firefox will scale it up on Retina displays and it will appear blurry. Always include both sizes in your extension package.

Tips for Firefox Add-on Icons

Include all 5 sizes (16, 32, 48, 96, 128) to cover every possible Firefox display context — from menus to the AMO store listing.
96×96 for Retina — this is the @2x version of the 48×48 icon. Firefox automatically selects the right size based on display density.
PNG with transparency works best — Firefox toolbar icons appear on the browser chrome, which varies by theme. Transparent backgrounds adapt to any color.
The AMO review team checks your icons — ensure they are clearly related to your add-on's purpose and follow Mozilla's content guidelines.
SVG icons are supported in manifest.json for browser_action icons in Firefox — SVG scales perfectly to any size but requires more careful design for small sizes.