Pinpoint where your JSON broke
Paste a URL or a blob of JSON. Pinpointjson parses it and, when it fails, points at the exact line and column and says what was expected in plain language — not "unexpected token at position 4471".
How it works
Paste a URL or JSON
Enter any public API endpoint or paste a snippet of JSON. The tool accepts both — URLs are fetched server-side, pasted text never leaves your browser.
Diagnose the response
Pinpointjson fetches the URL, reads what the server actually sent, and attempts to parse it as JSON. Every step is checked: content-type, body length, structure, and the HTTP status code.
Read the forensic report
The diagnostic output shows exactly where the parse failed, with the broken JSON context highlighted. When the response is an HTML error page wearing a JSON content-type, that mismatch is flagged as a separate finding.
What it detects
The tool examines the full response — not just whether it parses — and reports every finding independently.
Parse errors with context
Not "unexpected token at position 4471". Pinpointjson shows the exact line and column, the surrounding snippet, and a plain-language explanation of what the parser expected instead of what it found.
Content-type mismatches
An HTML error page returned as application/json is one of the most common causes of "my API is broken". The tool flags a mismatch between the declared content-type and the actual body type.
Error object dressed as success
Some APIs return {"status":"error","message":"..."} with a 200 HTTP status. Pinpointjson detects error-like fields in the response body and flags them even when the HTTP status looks fine.
Redirect tracking
The tool follows redirects (up to 5 hops) and reports each step — the URL, the status code, and when a hop leads to an unexpected destination.
Limitations
Hosts behind Cloudflare
A Cloudflare Worker cannot open a TCP connection to a host that is itself behind Cloudflare. Hosts such as example.com, cloudflare.com, and stackoverflow.com will report as unreachable rather than closed. This is a platform limitation, not a problem with your server. Verified reachable test targets include github.com, wikipedia.org, and news.ycombinator.com.
No email, no alerts
Pinpointjson has no email sender. It cannot notify you when a URL changes or when a parse result repeats. All results are displayed on-screen only and are not stored. If you need scheduled monitoring, that feature is planned but not yet available.
Try it now — no sign-up required
Paste a URL or a JSON blob and see the diagnosis in seconds.
Open the diagnostic tool