A Bit Of Access

Alt or not, a browser extension / add-on for Twitter and Tweetdeck

Published by (updated )

Alt or not is a browser extension / add-on for Chrome, Firefox, and Edge. Easily see which images include alt text or not on Twitter (also supports GIF) and TweetDeck, and get a warning when posting images without alt text.

It's often difficult or cumbersome to tell if images have alternative text on Twitter. Alternative (or alt) text is used to describe images for those who can't see the image, making them more accessible.

This extension shows which images are missing alternative text, and displays the alt text below the images when available.

Starting with version 0.5 it also warns users when images in a tweet have no alt text when tweeting.

Note: on TweetDeck descriptions are not displayed in the notifications column or on GIFs.

How does it work?

Install the extension / add-on on Chrome, Firefox, or Edge by downloading the correct version:

If needed, enable the extension, and you're done!


A tweet with the image description below the image
An image description is displayed.
A tweet with the no alt label displayed on a GIF
No image description was available on this GIF.
The no alt label on the tweet button while an image without alt text is visible in the composer
An image description should be provided.

Currently the extension has the following features (accurate for version 0.5 and above)

When reading tweets

  • Shows a red "No alt" label in the top left corner of images missing a description
  • Displays the description of images below the images in the tweet
  • Works on photos and animated GIFs for Twitter
  • Only works on photos where Tweetdeck includes the image descriptions (not on GIFs and some tweets in the notifications column
  • It should not impact the use of screen readers

When composing tweets

  • Shows hard to miss a red "No alt" label in the "send tweet" button when images lack alt text
  • Does not disable the tweet button, just in case

Planned features

The following feature(s) are under consideration for future updates:

  • Toggling features on or off


Update: 0.5 (14-05-2021)

Version 0.5 adds checking of alt text while composing tweets and has a few small optimizations.

Update: 0.4 (13-04-2021)

Version 0.4 improves the style on the displayed alt text for improved readability.

Update: 0.3 (27-02-2021)

Version 0.3 fixes an issue preventing alt text from displaying properly on some quote tweets on Twitter.

Update: 0.2 (26-02-2021)

Version 0.2 includes some optimizations and fixes some minor bugs:

  • Prevented "null" appearing below YouTube previews on Tweetdeck
  • Fixed positioning of alt text on Twitter on tweets with multiple described images
  • Fixed positioning of alt text on Twitter on quote tweets with described images in the tweet and quoted tweet

Can I see the source code?

Absolutely, whether you want to learn or check for potential issues with your own plugins, you can take a look at the code. On that page the code is divided in segments with additional comments.

Questions or suggestions

If you have questions about, or suggestions for the extension, you can let me know on Twitter.