Free online developer tools that never see your data

Re-indent minified or messy JSON with 2-space or 4-space indentation, catch syntax errors with exact line and column numbers, then copy or download the result.

Collapse multi-line JSON into a single compact line, with syntax still validated and the before-and-after byte size visible, for request bodies, log lines and message payloads.

Find out immediately whether a document is valid JSON, exactly where it breaks if it is not, and what the structure looks like once it parses.

Turn pseudo-JSON copied out of source code or logs — comments, single quotes, trailing commas, unquoted keys — into standard JSON that other languages will accept.

Turn JSON into an escaped string literal you can paste into source code, or decode an escaped blob from a log or database column back into readable JSON.

Decode \uXXXX sequences into readable characters, or encode accents, CJK, Cyrillic and emoji so a payload survives an ASCII-only pipeline.

Reorder keys at every nesting level so two payloads that differ only in field order become directly comparable, instead of producing a diff where every line changed.

Lay nested JSON out as a collapsible tree, search for a key or value, and copy the path to any node instead of counting braces to work out where a field lives.

Put two JSON documents side by side and see exactly which fields were added, removed or changed, after formatting and sorting away the noise of indentation and key order.

Pull the fields you need out of deeply nested JSON with one expression and watch the matches update as you type, instead of writing a throwaway extraction script.

Turn a JSON sample into export-ready TypeScript interfaces: nested objects become their own types, arrays become T[], and nulls fall back to any.

Turn JSON into Lombok @Data classes: nested objects become their own classes, snake_case keys become camelCase fields, and @JsonProperty keeps Jackson binding.

Generate Go structs with json tags from a JSON sample: numbers split into int and float64, nested objects become their own structs, and unknown shapes fall back to interface{}.

Turn a JSON sample into Pydantic BaseModel classes: typed fields, nested models written before their parents, and output that runs unchanged on Pydantic v1 and v2.

Two-way conversion between JSON and YAML: the YAML output uses 2-space indentation and keeps key order, and YAML input comes back as formatted JSON.

Convert both ways between JSON and XML: arrays become repeated tags, attributes come back as @_ keys, and the mapping rules are fixed in both directions.

Turn a JSON array into a CSV file you can open in a spreadsheet: the header is the union of every key, cells are quoted and escaped, and nested values become JSON text.

Encode and decode Base64 for text and images, with UTF-8 handling, the URL-safe alphabet, Data URL support and file size readouts.

Encode and decode URLs and query strings, with both encodeURIComponent and encodeURI, a batch mode for many lines and a query parameter table.

Split a JWT into header, payload and signature, read the time claims as dates, and verify an HS256 signature locally so the secret never leaves the page.

Five digests at once for text or a file, output as hex or Base64, computed locally so the file never leaves your machine.

Two-way conversion between Unix timestamps and dates, with automatic seconds / milliseconds detection, UTC, ISO 8601 and local readings, plus batch conversion and date arithmetic.

Compare two blocks of text or code line by line in a side-by-side view, ignoring whitespace or case when a config file throws up formatting noise.

Test any regular expression against real text with live highlighting, capture groups, a replacement preview and switchable flags.

Turn a cron expression into a plain-English sentence and the next 10 run times, with a field reference for 5-field and 6-field schedules.

Generate up to 100 UUID v4 values with the browser CSPRNG, and check existing UUIDs for validity, version and v1 timestamp.

Turn text or a URL into a QR code, optionally with a logo in the middle, with adjustable size, error correction and colors, exported as PNG or SVG.