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JSON Formatter

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HTML Viewer

Preview HTML markup in a sandboxed live iframe. Toggle raw and rendered views without leaving your browser.

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Why use our HTML Viewer?

100% private

Everything runs in your browser. Your data never leaves your device — safe for production payloads.

Instant results

No round trips, no rate limits, no login. Format, validate and inspect megabytes of JSON in milliseconds.

Standards-first

Follows RFC 8259 / ECMA-404 exactly. Reports errors with precise line and column diagnostics.

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