Overview
When you paste a link in a WhatsApp chat, the app fetches a preview — a thumbnail image, title, and description. This is generated by WhatsApp's built-in crawler, which reads Open Graph meta tags from the target page.
WhatsApp's preview bot runs from both the mobile app and WhatsApp Web/Desktop. On mobile, the preview is generated client-side — the device itself fetches the URL. On WhatsApp Web, it's fetched server-side. This dual behavior means you may see different results depending on how the link is shared.
Since WhatsApp is owned by Meta, it reads the same Open Graph tags as Facebook. However, the preview display is much smaller — typically a small thumbnail alongside the title and description — so image design considerations differ.
User-Agent Strings
WhatsApp Preview Bot identifies itself with the following user-agent strings:
WhatsApp/2.23.20.0WhatsApp/2.x.x (varies by version)How WhatsApp Preview Bot Handles OG Images
WhatsApp reads standard OG tags. The preview appears as a small thumbnail, so images should work well at small sizes.
Meta Tags Read
og:imageog:titleog:descriptionog:url| Preferred Size | 1200 × 630 |
| Minimum Size | 300 × 200 |
| Max File Size | 5 MB |
| Cache Duration | 72+ hours |
Caching Behavior
Extremely aggressive. WhatsApp caches link previews for 72 hours or more. There is no official tool to clear the cache — you must wait for it to expire or change the URL.
Fallback Behavior
Without an og:image tag, WhatsApp shows a text-only preview with the page title and domain name. No fallback image is extracted from the page.
Things to Know
- On mobile, the preview is fetched by the phone itself — if the phone is on a slow connection, the preview may fail to load.
- WhatsApp compresses images significantly. Use high-contrast designs that remain readable at thumbnail size.
- There is no official debugger tool. The only way to test is to send the link in an actual WhatsApp conversation.
- Cached previews persist even if you update your OG tags. The most reliable workaround is appending a query parameter like ?v=2 to the URL.
robots.txt
WhatsApp's compliance with robots.txt is inconsistent. Since mobile previews are fetched client-side (by the app, not a server-side crawler), robots.txt may not be checked. Server-side fetches generally respect it.
User-agent: WhatsApp
Allow: /How to Test
WhatsApp has no public debugger tool. The only reliable way to test your link preview is to send the URL in an actual WhatsApp conversation. Use a test group or chat with yourself to preview results.
- Send the link to yourself or a test group to see the preview before sharing widely.
- If the preview looks wrong, append a query parameter (e.g., ?v=2) to force a fresh fetch.
- Test on both mobile and WhatsApp Web — they may produce different results due to client-side vs. server-side fetching.
You can also use the MyOG OG Preview tool to check how your OG tags are configured before testing with WhatsApp Preview Bot.
FAQ
Why isn't WhatsApp showing my link preview image?
WhatsApp requires an og:image tag with an image at least 300 × 200 pixels. The image URL must be directly accessible (no authentication or paywalls). Also check that the image is under 5 MB and served over HTTPS. WhatsApp's aggressive cache means old previews may persist for 72+ hours.
How do I clear WhatsApp's link preview cache?
There is no official way to clear WhatsApp's cache. The most reliable workaround is to change the URL by appending a query parameter (e.g., example.com/page?v=2). This forces WhatsApp to treat it as a new URL and fetch fresh metadata.
Does WhatsApp compress OG images?
Yes. WhatsApp compresses images to reduce data usage, especially on mobile. Previews appear as small thumbnails. Use high-contrast images with large, readable text to ensure your OG image looks good after compression.
Related Bots
Test Your OG Images
Check how your Open Graph images appear to bots and crawlers. Preview your link cards before sharing.
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