---
title: "Alt text: definition for social media posting"
url: "https://get1post.com/glossary/alt-text.md"
canonical_url: "https://get1post.com/glossary/alt-text"
last_updated: "2026-10-23"
type: "conceptual"
summary: "What alt text means in social media posting, in plain words, with how 1Post handles it."
related: ["https://get1post.com/glossary.md"]
---

# Alt text: definition for social media posting

What alt text means in social media posting, in plain words, with how 1Post handles it.

Alt text is a short written description of an image, read aloud by screen readers and shown when the image does not load. Good alt text states what matters in the picture in a sentence. Instagram, Bluesky, Mastodon and X let you add it per image, and 1Post gives each image a field.

Describe the picture as you would to someone on the phone: what it shows, and any text in it.

Alt text is also how people who cannot see the image take part in the post.

## Questions

**How long should alt text be?**

One or two sentences. Networks set their own limits, and Mastodon, for example, publishes 1,500 characters on the instance we read.

## Related

- [Social media posting glossary: terms explained](https://get1post.com/glossary.md)