Adding alt text to images on Bluesky makes your posts accessible to people who use screen readers or have visual impairments. Alt text also helps the platform index your content for search and discovery. Without alt text, users relying on assistive technology only hear the word “image” instead of a description of what the photo shows. This article explains how to add alt text to images on the Bluesky web app and mobile apps. You will also learn best practices for writing effective descriptions.
Key Takeaways: Adding Alt Text to Bluesky Images
- Compose a new post and attach an image: The “Add alt text” link appears below the thumbnail after you upload a photo or graphic.
- Click or tap “Add alt text”: A text box opens where you can type a description of up to 1,000 characters.
- Write a concise, factual description: Describe the image content without editorial comments such as “beautiful” or “amazing”.
What Alt Text Does on Bluesky and Why It Matters
Alt text, short for alternative text, is a written description of an image that screen readers speak aloud. When you add alt text to an image on Bluesky, a user who is blind or has low vision can understand what the picture shows. Without alt text, the screen reader announces only the word “image” or “photo” and the user receives no information.
Bluesky requires you to add alt text manually for every image you upload. The platform does not auto-generate descriptions. This means you control what information is shared. Adding alt text also improves the searchability of your posts because the text appears in the Bluesky search index. If you post a screenshot of a news headline, for example, the alt text makes that headline text discoverable.
The alt text field on Bluesky accepts up to 1,000 characters. This is generous compared to many social platforms, which limit alt text to 100 to 300 characters. You can write detailed descriptions without worrying about truncation.
Steps to Add Alt Text to Images on Bluesky
The process is identical on the Bluesky web app, the iOS app, and the Android app. Follow these steps each time you attach an image to a post.
- Open the Bluesky app and tap the compose button
On the web, click the blue “New Post” button at the top of the left sidebar. On mobile, tap the blue pencil icon at the bottom center of the screen. The compose window opens. - Attach one or more images
Click or tap the camera icon in the compose window. Select images from your device. You can attach up to four images per post. Each image appears as a thumbnail below the text input area. - Locate the “Add alt text” link
Below each image thumbnail, a faint gray link reads “Add alt text”. Click or tap this link. A small text box opens directly below the image. - Type your description
Enter a clear, factual description of the image. Focus on what is visually important. For example: “A person wearing a blue jacket stands next to a white dog on a sandy beach. The sun is setting behind them.” The character counter at the bottom of the box shows how many characters you have used out of 1,000. - Save the alt text
Click or tap anywhere outside the text box to save the description. The “Add alt text” link changes to “Edit alt text” and shows a green checkmark icon to confirm that alt text has been added. - Post your message
Click the blue “Post” button in the top right corner of the compose window. The alt text is embedded in the image file and travels with the post.
To edit alt text after posting, tap the three-dot menu on your post, select “Edit”, and repeat the steps above. Your changes replace the previous description.
Common Mistakes When Writing Alt Text on Bluesky
Describing the image with subjective language
Alt text should be objective. Do not write “A beautiful sunset” or “An amazing cake.” Instead, write what the image actually shows: “An orange and pink sunset over a calm ocean” or “A three-layer chocolate cake with white frosting and strawberries on top.” Screen reader users want factual information, not an opinion.
Omitting alt text for decorative images
If an image is purely decorative and adds no information, you can leave the alt text field empty. Bluesky does not flag missing alt text. However, it is better to write a short description such as “Decorative border” or “Background pattern” so users know the image has no informational value.
Writing too little or too much text
Aim for one to three sentences. For a simple photo of a cat on a couch, “A gray cat sleeps on a blue couch” is sufficient. For a complex infographic, include the key data points and the chart type. Do not write a paragraph of background context that is not visible in the image. If the image contains text, reproduce that text exactly in the alt text.
Forgetting alt text when replying with images
Alt text is required for images in replies and quote posts, not only for original posts. The same “Add alt text” link appears below images in any compose window. Treat all images the same way regardless of the post type.
Alt Text Best Practices Summary
| Guideline | Do This | Avoid This |
|---|---|---|
| Start with the subject | “A woman wearing a red dress holds a microphone” | “There is a woman who is wearing a red dress and she is holding a microphone” |
| Mention key details | “A black dog with a red collar sits on green grass” | “A dog” |
| Describe actions | “Two children are jumping rope on a sidewalk” | “Children outside” |
| Transcribe visible text | “A sign reads ‘Welcome to Portland'” | “A sign with text” |
| Use neutral language | “A plate of spaghetti with meatballs” | “A delicious plate of spaghetti” |
If Alt Text Fails to Save
On rare occasions, Bluesky may not save the alt text you typed. This usually happens when you tap outside the text box while the field is still focused. To verify that alt text was saved, look for the green checkmark icon next to the “Edit alt text” link below the image. If you see “Add alt text” again after tapping away, the description was not saved. Tap the link again, retype the description, and tap outside the box a second time.
If the problem persists, close the compose window completely and open a new one. Attach the same image and repeat the steps. This clears any temporary cache issue in the app.
Conclusion
You can now add alt text to any image on Bluesky using the “Add alt text” link below each thumbnail in the compose window. Make it a habit to include a description every time you upload a photo, illustration, or screenshot. The 1,000-character limit gives you room to describe complex images such as charts or memes accurately. For a next step, review your recent posts and edit any images that still lack alt text. An advanced tip: if you post the same image again, copy the alt text from the original post to save time.