/tools/json-viewer
Online JSON Viewer & Formatter
View a collapsible tree, format and validate JSON syntax, search nested data, and download output locally.
JSON input
Result
/usage
How to view a JSON file online
- Paste JSON into the input, drag a
.jsonfile onto it, or choose a file from your device. - Pause briefly for the collapsible tree to refresh, or select View tree to process it immediately.
- Expand nested objects and arrays, search keys or values, and copy individual values or JSON Pointer paths.
- For files up to 20 MiB, switch to formatted text to copy, minify, or download a clean JSON file. Larger files stream formatted or minified output directly to disk.
/choose-a-view
JSON tree viewer or formatted text?
Use the tree for nested data
Open only the objects and arrays you need, search across keys and values, and copy an exact node value or path. Tree view is useful for exploring unfamiliar API responses without losing the surrounding structure.
Use formatted text for review and reuse
Switch to two-space-indented JSON when you need to read the full document, copy it into a request or configuration file, compare versions, or download a clean result.
/format-and-validate
Format, beautify, and validate JSON syntax
JSON formatter and pretty printer
Turn a minified API response or compact configuration file into readable, two-space-indented JSON. Use Format to beautify or pretty-print JSON, then copy the formatted text or download it. Minify removes unnecessary whitespace when you need compact output.
JSON syntax validation and errors
Strict validation identifies the line and column of syntax problems such as missing commas, mismatched brackets, or invalid quotes. This checks JSON syntax; it does not validate a document against a JSON Schema. When safe, the tree can separately interpret common partial-input mistakes and clearly labels the result as interpreted.
/explore
Explore a searchable JSON tree and copy paths
Search nested keys and values
Browse objects and arrays as a collapsible tree instead of scanning a wall of text. Search highlights matching keys and primitive values, with previous and next controls for moving through results. Branches render only when opened so deeply nested JSON remains manageable.
Copy JSON Pointer paths
Copy a node value or its RFC 6901-style JSON Pointer path, such as /orders/0/id. This makes it easier to identify the exact field behind an API error, discuss a configuration value with a teammate, or document where a value appears in a payload.
/large-files-and-debugging
Handle large JSON files privately
Editable JSON to 20 MiB; file-backed JSON to 4 GiB
JSON up to 20 MiB uses the editable workspace. Larger selected files, up to 4 GiB, stay file-backed: a dedicated worker validates UTF-8 and JSON syntax from bounded slices, and tree branches, search results, copied values, and expansion are deliberately capped. The input is not uploaded, written to browser storage, placed in the URL, or included in analytics events.
A practical API debugging workflow
Paste a failing API response, validate its syntax, format it for review, and search for a request ID or error field. Expand the matching branch, copy its JSON Pointer path, and share only the relevant path or value. The complete response remains on your device throughout the workflow.
Formatting and minifying a file-backed document require a browser with direct filesystem writing. Output is streamed to the destination rather than retained in memory. For intentional local transfer, open Share and create a .ddshare package; Data Demon can compress or password-protect up to 4 GiB without uploading it.
/evidence
Reproducible JSON viewer evidence
The built-in example is the same synthetic sample.json published in the repository. Data Demon Systems maintains it as a test input for strict parsing, collapsible object and array rendering, search, formatting, minifying and JSON Pointer paths.
The public JSON Viewer fixture and methodology document the supported operations and deliberate 20 MiB editable and 4 GiB file-backed limits. Syntax behaviour follows RFC 8259, while copied paths use RFC 6901 JSON Pointer notation.
Need to compare two documents rather than inspect one? Use the JSON Diff & RFC 6902 Patch tool.
/faq
JSON formatter, viewer, and validator questions
Is my JSON uploaded or stored?
No. JSON input is processed in a dedicated worker inside your browser. It is not uploaded, saved to browser storage, or included in analytics events.
What is the maximum JSON file size?
Pasted and editable JSON is limited to 20 MiB. Selected UTF-8 JSON files can be up to 4 GiB in file-backed mode, where bounded worker scans power lazy inspection without loading the complete source into RAM. Direct-to-disk formatting and minifying require compatible filesystem support.
What is a .ddshare file?
It is a local Data Demon package for compressed or password-protected source. The file can contain up to 4 GiB, stays on your device, and must be sent to the recipient using your chosen file-transfer service.
Can this repair invalid JSON?
It attempts conservative repairs for common partial input, including comments, trailing commas, unfinished strings, and missing closing brackets. The status line always tells you when the result was interpreted rather than strictly valid.