{ }jsonkit

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100% client-side — your data never leaves this tab

Free developer tools that never see your data.

Format, validate and convert JSON, generate code, inspect URLs and SQL, or work with QR codes — 53 tools that run entirely in your browser. No uploads, no signup, results as you type.

Format JSON now →Browse all 53 tools

Press ⌘K anywhere to jump to a tool

jsonkit.com/json-formatter✓ valid · 0.4 ms

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{ "id": "usr_8x42", "name": "Ada Lovelace", "active": true, "roles": ["admin", "editor"], "plan": { "seats": 5 }

30free tools

0 bytessent to any server

100%client-side

Freeforever

Every JSON tool you reach for

Each tool lives on its own page, pre-filled with sample data and usable the second it loads.

Format

{ }JSON Formatter

Beautify or minify JSON — runs locally, nothing is uploaded./json-formatter

≡→JSON Minifier

Strip whitespace for the smallest production payload./json-minifier

\"JSON Escape / Unescape

Stringify JSON for embedding in code — and back./json-escape

a→zJSON Sorter

Recursively sort object keys for clean, diffable JSON./json-sorter

⇄{}JSON Flattener

Flatten nested JSON to dot-path keys, or expand it back./json-flattener

Fix common syntax mistakes and return clean, valid JSON locally./json-repair

█JSON Redactor

Mask selected keys and dot paths before sharing a payload./json-redactor

SQLSQL Formatter

Reformat common SQL while preserving strings, comments, and identifiers./sql-formatter

Validate

✓JSON Validator

RFC 8259 strict mode with inline error markers./json-validator

±JSON Diff / Compare

Spot added, removed and changed values between two documents./json-diff

§JSON Schema Generator

Infer a JSON Schema from sample data — or validate against one./json-schema-generator

Decode header, payload and signature — with expiry check./jwt-decoder

ΔJSON Patch / Merge Patch

Generate and apply RFC 6902 JSON Patch and RFC 7386 merge patches./json-merge-patch

kbJSON Size Analyzer

Find the heaviest keys and paths in your JSON payload./json-size-analyzer

api✓OpenAPI Validator

Check API structure, operations, responses and local references./openapi-validator

Convert

→csvJSON to CSV

Flatten nested JSON into spreadsheet-ready rows./json-to-csv

csv→CSV to JSON

Header detection and type inference, automatically./csv-to-json

⇄ymlJSON ⇄ YAML

Convert both directions — comment-safe./json-to-yaml

⇄xmlJSON ⇄ XML

Attributes, arrays and namespaces handled./json-to-xml

→tsJSON to TypeScript

Nested types with optional-property detection./json-to-typescript

b64Base64 Encode / Decode

UTF-8 safe, with a url-safe variant — fully local./base64-encode-decode

%2FURL Encode / Decode

Percent-encode query values or whole URLs — RFC 3986./url-encode-decode

clkTimestamp Converter

Unix seconds, milliseconds, ISO 8601 or "now" — to human dates./timestamp-converter

→zJSON to Zod

Infer a Zod v4 schema with nested named object schemas./json-to-zod

→pyJSON to Pydantic

Infer Pydantic v2 models with nested classes from sample JSON./json-to-pydantic

→goJSON to Go

Typed structs with json tags and optional detection./json-to-go

→javaJSON to Java

Infer Java 17 records or POJO classes from sample JSON./json-to-java

⇄jsonlJSON ⇄ JSONL

Array to newline-delimited JSON and back./json-to-jsonl

5→JSON5 / JSONC to JSON

Strip comments and trailing commas — get strict JSON./json5-to-json

▦→QR Code Decoder

Read a QR code from an image — private, instant and local./qr-decode

⇄tomlJSON ⇄ TOML

Convert configuration data in either direction without an upload./json-to-toml

2↔16Number Base Converter

Convert exact integers between binary, octal, decimal, and hexadecimal./number-base-converter

→C#JSON to C#

Create nullable C# models with nested types and JSON attributes./json-to-csharp

→ktJSON to Kotlin

Infer data classes, nullability and kotlinx.serialization names./json-to-kotlin

→rsJSON to Rust

Build nested Rust structs with Option, Vec and Serde derives./json-to-rust

→swiftJSON to Swift

Generate Codable structs, optionals, arrays and CodingKeys./json-to-swift

→phpJSON to PHP

Create typed PHP 8 DTO models and JSON key maps./json-to-php

Query & Generate

$.JSONPath / JQ Tester

Query playground with live results as you type./jsonpath-tester

◌Mock JSON Data Generator

Schema-driven fake names, emails, dates and UUIDs./mock-json-generator

idUUID / NanoID Generator

Batch-generate v4, v7 or NanoID ids — locally, with the crypto RNG./uuid-generator

#Hash Generator

Hash any text to a hex digest with SHA-256, SHA-1 or MD5./hash-generator

Live matches, named groups and capture details as you type./regex-tester

▦+QR Code Generator

Turn text or a URL into a downloadable QR code./qr-code-generator

⌁▦Wi-Fi QR Generator

Let guests join your network with one scan./wifi-qr-code-generator

§→{}Schema Sample Generator

Create deterministic example JSON from a JSON Schema./json-schema-sample-generator

jmesJMESPath Tester

Explore JSON with projections, filters, slices, pipes and functions./jmespath-tester

*/5Cron Expression Parser

Validate five-field cron schedules and preview their next runs./cron-expression-parser

Inspect every URL component and repeated query parameter locally./url-parser

◉▦vCard QR Generator

Put complete contact details behind one scannable code./vcard-qr-code-generator

▣▦Event QR Generator

Turn an event into a calendar-ready code guests can scan./event-qr-code-generator

@▦Email & SMS QR Generator

Prefill a recipient and message for email or text./email-sms-qr-code-generator

⌖▦Location QR Generator

Share exact latitude and longitude with a single scan./location-qr-code-generator

▐▐▐Barcode Generator & Decoder

Create common barcode formats or inspect an image locally./barcode-generator-decoder

Built the way developers actually work

🔒 zero-upload

Paste production data safely

Everything runs client-side. Disconnect from the internet — the tools keep working.

⚡ instant

Results as you type

No submit buttons. Format, validate and convert live, with errors marked by line and column.

⌨ keyboard-first

Shortcuts everywhere

⌘K to jump between tools, ⌘↵ to run, ⌘C to copy output. Fully operable without a mouse.

↗ shareable

Send a link, not a file

Tool and input encode into the URL — with a privacy warning before you share.

How JsonKit compares

Against the usual ways developers wrangle JSON.

{ }jsonkit

Typical online tools

CLI (jq, sed…)

IDE plugins

Data stays on your machine

✓ always

✗ often uploaded

✓

✓

Zero install, works anywhere

✓

✓

✗ install + PATH

✗ per-editor

53 tools in one place

✓ one ⌘K away

✗ one site each

~ scriptable

✗ format only

Visual diff & error markers

✓ line + column

~ varies

✗ text output

✓

Shareable result links

✓ URL-encoded

~ rare

✗

✗

Cost

Free

Free, ad-heavy

Free

Free–paid

CLI tools and IDE plugins are great — JsonKit is for when you want an answer in the next five seconds, on any machine.

Frequently asked questions

Is my JSON uploaded anywhere?

No. Every tool runs entirely in your browser with JavaScript. You can disconnect from the internet and they keep working — there is no server to send data to.

Are the tools really free?

Yes — all 53 tools are completely free, with no signup, no Pro tier and no ads.

What is the maximum file size?

There is no paid limit. Because everything runs locally, how large a file you can process depends on your browser and how much memory your device has available.

Can I share a result with a teammate?

Yes — the tool and your input encode into the URL. You'll see a privacy warning first so secrets don't end up in chat logs.