Paste an identifier-map JSON and a stack trace. Click Demangle. The substitution runs entirely in your browser — no network call, no server upload, no third-party storage.
Privacy check. Everything you paste below stays in this page's memory. There is no fetch, no XHR, no analytics beacon for the textarea contents. View source if you want to confirm. The same algorithm runs in the offline jso-symbolicate npm package — this demo just exposes it through a textarea UI.
Identifier map (paste JSON or block text)
0 entries
Stack trace (paste the crash text)
0 lines
Ready
Want this in your CI or runtime? See the symbolication workflow doc for the npm CLI and the six error-reporter integrations (Sentry, Bugsnag, Rollbar, Datadog, Honeybadger, Raygun).