Why WhatsApp previews are hard to test
WhatsApp has no public debugger and publishes few details about link previews. The usual test is to send yourself the link, which shows the result but not the reason for it. A preview that fails once may also work the next time, because the app builds it when the link is typed, so a slow page or heavy image can leave a message with no preview.
This checker fetches your page, shows the preview it expects, and lists each problem with its fix. It’s an independent tool, and the preview is an approximation based on observed behavior, so send yourself the link for the final check.
The tags WhatsApp reads
WhatsApp reads Open Graph tags and falls back to your <title> and meta description for the text. There’s no fallback we can rely on for the image, so set og:image yourself:
<meta property="og:title" content="Your page title">
<meta property="og:description" content="One or two sentences about the page.">
<meta property="og:image" content="https://example.com/images/card.jpg">
<meta property="og:image:width" content="1200">
<meta property="og:image:height" content="630">Expect up to about 100 characters of title and 160 of description, and fewer on a narrow phone screen.
Keep the image file small
File size is a common problem on WhatsApp. An image that works on Facebook can still be dropped here, and you won’t get an error. WhatsApp doesn’t publish its limit: our health report warns above about 600 KB, while many developers report trouble above about 300 KB. Aim for under 300 KB to be safe.
- Use a JPEG at 1200×630 with moderate compression. It’s usually far smaller than a PNG of a photo.
- If one image must serve every platform, compress it for WhatsApp, because the others accept much larger files.
- Make sure the image server responds quickly. A slow image can miss the moment the preview is built.
Large image or small thumbnail?
Based on observed behavior, WhatsApp shows a wide image when the file is at least 300 pixels wide and wider than 1.3:1. A narrower or nearly square image becomes a small thumbnail beside the text. A 1.91:1 image at 1200×630 gets the large layout. The cheat sheet compares these rules across platforms.
Why your WhatsApp preview isn’t showing
- No image, but the text appears: the file is probably too large. Check its size in the health report.
- The image URL can’t be used: it’s relative, uses http, or redirects. Use a direct, absolute https URL.
- No preview at all: the page may be slow or blocking requests, or the sender pressed send before the preview appeared.
- The tags are added by JavaScript: link previews don’t run it, so the tags must be in the HTML your server sends.
- It works here but not on one phone: privacy settings, an old app version or a poor connection on that device can affect the preview.
Refreshing a preview WhatsApp has cached
There’s no public refresh tool, and messages you’ve already sent keep the preview they have. To see your changes sooner, send the URL with a harmless query string such as ?v=2, which WhatsApp treats as a new link. If you changed the image, also give it a new URL. Then check your page again to confirm the tags are right.