An independent, privacy-first JSON toolkit built by a working developer for working developers.
JSON Web Tools is a free online toolkit at jsonwebtools.com with more than 100 utilities for working with JSON and adjacent data formats. It covers everything a developer reaches for during an average day: validating malformed payloads, beautifying minified responses, diffing two API outputs, generating TypeScript or Python types from a sample, decoding a JWT, converting between JSON, CSV, YAML, XML, SQL, and Excel, building JSON Schemas, mocking realistic test data, and dozens of smaller tasks.
Every single tool runs entirely inside your browser using JavaScript executed on your own machine. Your JSON content is never uploaded, transmitted, logged, or stored on our servers. There is no upload step because there is no server doing the work — only your CPU, your browser, and the JavaScript we ship with each page.
The story behind the project is unglamorous. While debugging a production incident in 2025, the operator found himself bouncing between four different "free JSON tools" sites: one to format, another to diff, a third to convert to YAML, and a fourth to decode a JWT. Three of those sites required uploading the payload to an unknown server. Two were buried in pop-up advertising. One had a paywall that activated mid-task. None worked offline on a flight.
JSON Web Tools was built to be the site that solves that problem: every tool a JSON-handling developer needs, on a single domain, free, private, fast, and usable without installing anything. The goal is to make working with JSON feel like using a well-built native utility — not like running a gauntlet of ads and signup walls.
The mission is simple: make high-quality developer tooling freely available without harvesting user data. Most "free" web tools earn revenue by funnelling pasted content into analytics pipelines, training data sets, or ad personalisation profiles. We believe that is incompatible with the level of trust developers extend when they paste a customer record, an authentication token, or a piece of internal API output into a textbox.
JSON Web Tools is funded entirely by display advertising shown alongside the tools. We never inspect, transmit, or monetise the content you paste. The ads support hosting and continued development. That is the entire business model.
JSON Web Tools is operated by Saurabh Goyal, an independent software developer based in India. The project is solo-maintained, which means a real human reads the support inbox and ships the bug fixes. There is no team page to populate with stock photos because there is no team — just one developer who codes, designs, deploys, and replies to email.
Being independent has trade-offs. Response times to bug reports are usually within one to two business days, but occasionally longer if a release is in progress. There is no enterprise support tier, no SLA, and no on-call rotation. In exchange, there is no corporate roadmap pulling features away from what developers actually need, and no investor pressure to start charging for things that should stay free.
Selected highlights from the 100+ tools available today:
Tools are added when a real workflow needs them, not to inflate a feature count. The current focus areas are: improving handling of very large JSON files (10MB+) without locking the browser, adding more language targets for type generation, and writing deeper guides for JSON Schema and JSONPath. Suggestions from users frequently turn into tools — if a workflow is missing, email and it will be considered.
The site will remain free. There are no plans to introduce a paid tier, gate features behind logins, or sell user data. If that ever changes, it will be announced clearly on the homepage well in advance.
Bug reports, feature suggestions, partnership inquiries, or just hello — write to admin@jsonwebtools.com. For everything else, see the Contact page or the FAQ.