Visualize JSON structure as an indented tree — see nested objects and arrays at a glance. Collapse deep branches to navigate large payloads — free, local, no signup.
Content reviewed October 2026 · About Toolzum
Prettify raw JSON and XML API responses with indentation, key sorting, and syntax validation. Read nested payloads at a glance — local processing, free, no signup.
Decode Base64 strings and pretty-print JSON data — paste encoded text to see the decoded result instantly. Inspect API payloads and tokens readably — free, local, no signup.
Generate realistic mock JSON from field specs — names, emails, dates, nested objects. Fill frontends before backends exist — local generation, free, no signup.
Convert JSON objects to YAML format with proper key-value formatting and nested structure support. Everything runs locally in your browser.
Turn messy client CSV and Excel sheets into clean JSON arrays or keyed objects with column mapping. Developers convert 50 exports without hand-editing — local SheetJS work, 2 free batches a day.
JSON structure as an expandable/collapsible tree with nested objects, arrays, and leaf values. Colors distinguish keys (strings), numbers, booleans, and null values.
Yes. Click any object or array node to expand or collapse it. This helps navigate large JSON documents by hiding irrelevant branches.
Yes. Click on any leaf value to copy it to clipboard. The tree preserves the full path for context.
Yes. If the JSON is malformed, the viewer shows an error with the line number and position of the syntax issue.
No. All visualization happens locally in your browser. No JSON data is sent to any server.
Indent is 2 spaces per depth; array items print as [0]: ... lines, empty arrays as [], empty objects as {}, null as null and strings quoted. The default document nests address {city, zip} and hobbies [reading, coding] to show both.
JSON Path Query Builder
Query JSON data using dot-notation path expressions with wildcard support. Code never leaves your device — formatting and validation run locally in your browser.
JSON Formatter
Pretty-prints raw JSON with configurable indent width, key sorting, and bracket collapsing options while flagging syntax errors with exact.