Viewport Meta Tag Checker
Check the viewport meta tag — the one line that decides whether your page is usable on a phone.
- 100% free
- No sign-up
What is Viewport Meta Tag Checker?
The viewport meta tag tells a mobile browser to lay the page out at the device's own width instead of pretending to be a 980-pixel desktop and scaling the result down.
Without it, a responsive stylesheet never takes effect and the page arrives zoomed out and unreadable. The tag is one line and almost always the same line, so the interesting failures are not typos but deliberate ones: user-scalable=no and a low maximum-scale both block pinch-zoom, which fails WCAG 1.4.4 and makes the page unusable for anyone who needs to magnify text. This checker reports all three.
How to use Viewport Meta Tag Checker
- 1
Fetch or paste
Enter a URL, or paste the tag on its own.
- 2
Confirm width=device-width
This is the part that makes responsive CSS work at all.
- 3
Remove any zoom blocking
user-scalable=no is an accessibility failure, and iOS Safari has ignored it for years anyway — so it costs you compliance and buys you nothing.
- 4
Allow at least 2× zoom
WCAG expects content to survive 200% magnification. A maximum-scale below 2 prevents that.
Everything this tool
does for you
- Missing-tag detection
- width=device-width verification
- Zoom-blocking detection with the WCAG reference
- maximum-scale threshold check
- Reads a live URL or pasted HTML
- Free, no signup, no daily limit
Further reading
Related free tools
Frequently asked questions
Beyond this tool
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- Detects a missing or malformed viewport
- Flags disabled zoom as the accessibility failure it is
- Checks maximum-scale against the 200% zoom requirement
- Works on a live URL or pasted HTML
- Free, no account, no daily limit