Frequently Asked Questions

JSON Hero is a free online JSON viewer, formatter, and editor. It runs entirely in your browser — no data is ever sent to a server. You can format, minify, validate, search, and edit JSON with syntax highlighting and a collapsible tree view.

Go to jsonhero.dev, paste your JSON into the editor, and click "Format". Your JSON will be pretty-printed with proper indentation and syntax highlighting. You can also load JSON from a URL or upload a file.

Yes, JSON Hero is completely free with no sign-up required. There are no premium tiers, no ads, and no usage limits. It's built as a free tool for developers.

Your data is completely safe. JSON Hero runs 100% client-side in your browser. No JSON data is ever sent to any server. There is no backend. Your data never leaves your device.

Yes. Click the "Minify" button in the toolbar or press Cmd/Ctrl+Shift+M to compact your JSON to a single line, removing all whitespace. This is useful for reducing payload size.

Yes. When you click "Format", JSON Hero validates your input using JSON.parse. If the JSON is invalid, it shows a warning toast and provides best-effort formatting using a tolerant parser so you can still see and fix the structure.

Yes. Click "Load JSON" in the toolbar, enter any public URL in the URL field, and click "Fetch". JSON Hero will download the JSON from that endpoint and display it in the editor. This is great for inspecting API responses.

JSON Hero works in all modern browsers including Google Chrome, Mozilla Firefox, Apple Safari, and Microsoft Edge. It requires JavaScript to be enabled.

Yes. Use the search bar in the toolbar to find text within your JSON document. Matches are highlighted in yellow, and you can navigate between them with the Next/Previous buttons or by pressing Enter. The match counter shows your position in the results.

Click the fold arrow (▶) next to any object or array to collapse it. The collapsed section shows a placeholder like {...} or [...]. Use the "Collapse all" and "Expand all" toolbar buttons to fold or unfold the entire document at once.

Yes. If you paste a JSON string that contains escaped characters (like \"), JSON Hero detects this and offers an "Unescape" button. Clicking it unescapes and re-formats the nested JSON so you can view it properly.

Yes. JSON Hero supports several keyboard shortcuts: Cmd/Ctrl+Shift+M to minify, Enter to jump to the next search match, Cmd/Ctrl+Enter for the previous match, and standard text editing shortcuts in the editor.