AI alt text generator for Firefox
Generate accurate alt text for any image without leaving Firefox. Right-click, get a clean description in seconds, and paste it wherever you're working.
THE PROBLEM
Three reasons a blank alt field keeps costing you
Accessibility: A screen reader can't describe an image on its own. With no alt text, anyone using assistive technology hits a blank where your content should be. Descriptive alt text is a baseline requirement of WCAG 2.1 AA, and it's what the ADA and the European Accessibility Act expect.
The workflow gap: Half the time you're adding images somewhere with no plugin: a social post, a headless setup, a client's site you can't install anything on. Stopping to hand-write a good description kills your momentum, so the field ends up empty.
How to generate alt text in Firefox
Add the add-on to Firefox
Install AltTextLab from Mozilla Add-ons and pin it to your toolbar. It's a standard add-on, with nothing to configure at the code level.
Connect your API key
Open AltTextLab's settings from the toolbar puzzle icon and drop in the API key from your account. That links the add-on to your monthly credits.
Right-click any image to generate alt text
On any public page, right-click an image and pick AltTextLab: Get alt text. A clean description appears in a popup a second, ready to copy.
Descriptions that hold up, not just labels
Works on any website
Context-aware descriptions
130+ languages
Private by design
WCAG 2.1 AA compliant output
Four writing styles
Teams that stopped writing alt text by hand
Does the add-on automatically apply alt text to my images, or do I have to paste it manually?
The Firefox add-on generates alt text and gives you a copy-ready result — you then paste it wherever you need it. If you want alt text written into your site automatically and in bulk, the native integrations for WordPress, Shopify, Webflow, and 10+ other platforms do that, and so does the API for any other website. The add-on is best for quick, one-off descriptions and for pages where no native integration exists.
How much does the Firefox add-on cost?
Nothing to start. Every account includes 25 image credits a month on the free plan, with no card required, and the add-on draws from those. If you need more volume, paid plans start at $5 a month, and pay-as-you-go credits are available if you'd rather not subscribe.
Which websites does it work on?
Any public web page, on any CMS or platform, as long as the image is publicly reachable. Images behind a login or otherwise blocked may not generate.
What data does the add-on collect, and is it compliant with Firefox's data disclosure requirements?
The add-on only accesses the specific image you right-click and request generation for. It does not track your browsing history, read other page content, or monitor your activity across sites. That image is sent to AltTextLab's servers for analysis to generate the description, and is not stored afterward or used to train AI models.
As of November 2025, Mozilla requires all new Firefox extensions to explicitly disclose what data they collect directly in the installation prompt and on the extension's Add-ons Marketplace listing. AltTextLab's data collection practices are fully disclosed there in line with this requirement, so you can review exactly what's accessed before installing.
Does using the add-on use credits from my AltTextLab account?
Yes. Each image you generate alt text for uses one credit from your AltTextLab account — the same shared credit pool used across all integrations (CMS plugins, Web Snippet, API, and the Chrome Extension). Credits aren't specific to any one browser or tool. You can check your balance and usage history anytime in your AltTextLab dashboard.
Never leave an image blank again
