Format your bot messages
Message formatting enables you to bring out the best in bot messages. You can format your bot messages to include rich cards as attachments that contain interactive elements, such as buttons, text, and images.
Note
The bot message size limit is 40 KB. If the bot message size limit exceeds 40 KB, bot receives a 413 status code (RequestEntityTooLarge), which contains the error code MessageSizeTooBig. The bot message size limit includes the entire message payload encoded as UTF-16 and doesn't include Base64 encoded images.
Format text content
To format your bot messages, you can set the optional TextFormat property to control how your bot message's text content is rendered.
Microsoft Teams supports the following formatting options:
TextFormat value |
Description |
|---|---|
plain |
The text must be treated as raw text with no formatting applied. |
markdown |
The text must be treated as Markdown formatting and rendered on the channel as appropriate. |
xml |
The text is simple XML markup. |
Teams supports a subset of markdown and xml or HTML formatting tags. Your bot can also mention other users and tags in text messages posted in channels. For more information, see add mentions to your messages.
The following limitations apply to formatting:
- Text-only messages don't support table formatting.
- Rich cards support formatting in the text property only, not in the title or subtitle properties.
- Rich cards don't support Markdown or table formatting.
After you format text content, ensure that your formatting works across all platforms supported by Teams.
Cross-platform support
Some styles aren't supported across all platforms. The following table provides a list of styles and which of these styles are supported in text-only messages and rich cards:
| Style | Text-only messages | Rich cards - XML only |
|---|---|---|
| Bold | ✔️️ | ❌ |
| Italic | ✔️ | ✔️ |
| Header (levels 1–3) | ❌ | ✔️ |
| Strikethrough | ❌ | ✔️ |
| Horizontal rule | ❌ | ❌ |
| Unordered list | ❌ | ✔️ |
| Ordered list | ❌ | ✔️ |
| Preformatted text | ✔️ | ✔️ |
| Blockquote | ✔️ | ✔️ |
| Hyperlink | ✔️ | ✔️ |
| Image link | ❌ | ❌ |
After checking cross-platform support, ensure that support by individual platforms is also available.
Support by individual platform
Support for text formatting varies by type of message and platform.
Text-only messages
The following table provides a list of styles, which are supported on desktop, iOS, and Android:
| Style | Desktop | iOS | Android |
|---|---|---|---|
| Bold | ✔️ | ✔️ | ✔️ |
| Italic | ✔️ | ✔️ | ✔️ |
| Header (levels 1–3) | ❌ | ❌ | ❌ |
| Strikethrough | ✔️ | ✔️ | ❌ |
| Horizontal rule | ❌ | ❌ | ❌ |
| Unordered list | ✔️ | ❌ | ❌ |
| Ordered list | ✔️ | ❌ | ❌ |
| Preformatted text | ✔️ | ✔️ | ✔️ |
| Blockquote | ✔️ | ✔️ | ✔️ |
| Hyperlink | ✔️ | ✔️ | ✔️ |
| Image link | ❌ | ❌ | ❌ |
AI-generated content messages
AI labels, citations, feedback buttons, and sensitivity labels in your bot’s messages improve user engagement and foster transparency and trust.
- AI label enables users to identify that the message was generated using AI.
- Citations enables users to refer to the source of the bot's message through in-text citations and references.
- Feedback buttons enables users to provide positive or negative feedback to the bot's messages.
- Sensitivity label enables users to understand the confidentiality of the bot's message.
For more information, see bot messages with AI-generated content.