JSON Forge: Privacy-First JSON Formatter in Your Browser

Last week I needed to debug a nested API response — the kind with five levels of objects, arrays inside arrays, and keys that look like someone fell asleep on the keyboard. Simple enough task. I just needed a JSON formatter.

**👉 Try JSON Forge now: [jsonformatter.orthogonal.info](https://jsonformatter.orthogonal.info)** — no install, no signup, runs entirely in your browser.

So I opened the first Google result: jsonformatter.org. Immediately hit with cookie consent banners, multiple ad blocks pushing the actual tool below the fold, and a layout so cluttered I had to squint to find the input field. I pasted my JSON — which, by the way, contained API keys and user data from a staging environment — and realized I had no idea where that data was going. Their privacy policy? Vague at best.

Next up: JSON Editor Online. Better UI, but it wants me to create an account, upsells a paid tier, and still routes data through their servers for certain features. Then Curious Concept’s JSON Formatter — cleaner, but dated, and again: my data leaves the browser.

I closed all three tabs and thought: I’ll just build my own.

Introducing JSON Forge

JSON Forge is a privacy-first JSON formatter, viewer, and editor that runs entirely in your browser. No servers. No tracking. No accounts. Your data never leaves your machine — period.

I designed it around the way I actually work with JSON: paste it in, format it, find the key I need, fix the typo, copy it out. Keyboard-driven, zero friction, fast. Here’s what it does:

• Format & Minify — One-click pretty-print or compact output, with configurable indentation
• Sort Keys — Alphabetical key sorting for cleaner diffs and easier scanning
• Smart Auto-Fix — Handles trailing commas, unquoted keys, single quotes, and other common JSON sins that break strict parsers
• Dual View: Code + Tree — Full syntax-highlighted code editor on the left, collapsible tree view on the right with resizable panels
• JSONPath Navigator — Query your data with JSONPath expressions. Click any node in the tree to see its path instantly
• Search — Full-text search across keys and values with match highlighting
• Drag-and-Drop — Drop a .json file anywhere on the page
• Syntax Highlighting — Color-coded strings, numbers, booleans, and nulls
• Dark Mode — Because of course
• Mobile Responsive — Works on tablets and phones when you need it
• Keyboard Shortcuts — Ctrl+Shift+F to format, Ctrl+Shift+M to minify, Ctrl+Shift+S to sort — the workflow stays in your hands
• PWA with Offline Support — Install it as an app, use it on a plane

Why Client-Side Matters More Than You Think

Here’s the thing about JSON formatters — people paste everything into them. API responses with auth tokens. Database exports with PII. Webhook payloads with customer data. Configuration files with secrets. We’ve all done it. I’ve done it a hundred times without thinking twice.

Most online JSON tools process your input on their servers. Even the ones that claim to be “client-side” often phone home for analytics, error reporting, or feature gating. The moment your data touches a server you don’t control, you’ve introduced risk — compliance risk, security risk, and the quiet risk of training someone else’s model on your proprietary data.

JSON Forge processes everything with JavaScript in your browser tab. Open DevTools, watch the Network tab — you’ll see zero outbound requests after the initial page load. I’m not asking you to trust my word; I’m asking you to verify it yourself. The code is right there.

The Single-File Architecture

One of the more unusual decisions I made: JSON Forge is a single HTML file. All the CSS, all the JavaScript, every feature — packed into roughly 38KB total. No build step. No npm install. No webpack config. No node_modules black hole.

Why? A few reasons:

1. Portability. You can save the file to your desktop and run it offline forever. Email it to a colleague. Put it on a USB drive. It just works.
2. Auditability. One file means anyone can read the entire source in an afternoon. No dependency trees to trace, no hidden packages, no supply chain risk. Zero dependencies means zero CVEs from upstream.
3. Performance. No framework overhead. No virtual DOM diffing. No hydration step. It loads instantly and runs at the speed of vanilla JavaScript.
4. Longevity. Frameworks come and go. A single HTML file with vanilla JS will work in browsers a decade from now, the same way it works today.

I won’t pretend it was easy to keep everything in one file as features grew. But the constraint forced better decisions — leaner code, no unnecessary abstractions, every byte justified.

The Privacy-First Toolkit

JSON Forge is actually part of a broader philosophy I’ve been building around: developer tools that respect your data by default. If you share that mindset, you might also find these useful:

• QuickShrink — A browser-based image compressor. Resize and compress images without uploading them anywhere. Same client-side architecture.
• PixelStrip — Strips EXIF metadata from photos before you share them. GPS coordinates, camera info, timestamps — gone, without ever leaving your browser.
• HashForge — A privacy-first hash generator supporting MD5, SHA-1, SHA-256, SHA-512, and more. Hash files and text locally with zero server involvement.

Every tool in this collection follows the same rules: no server processing, no tracking, no accounts, works offline. The way developer tools should be.

What’s Under the Hood

For the technically curious, here’s a peek at how some of the features work:

The auto-fix engine runs a series of regex-based transformations and heuristic passes before attempting JSON.parse(). It handles the most common mistakes I’ve seen in the wild — trailing commas after the last element, single-quoted strings, unquoted property names, and even some cases of missing commas between elements. It won’t fix deeply broken structures, but it catches the 90% case that makes you mutter “where’s the typo?” for ten minutes.

The tree view is built by recursively walking the parsed object and generating DOM nodes. Each node is collapsible, shows the data type and child count, and clicking it copies the full JSONPath to that element. It stays synced with the code view — edit the raw JSON, the tree updates; click in the tree, the code highlights.

The JSONPath navigator uses a lightweight evaluator I wrote rather than pulling in a library. It supports bracket notation, dot notation, recursive descent ($..), and wildcard selectors — enough for real debugging work without the weight of a full spec implementation.

Developer Setup & Gear

I spend most of my day staring at JSON, logs, and API responses. If you’re the same, investing in your workspace makes a real difference. Here’s what I use and recommend:

• LG 27″ 4K UHD Monitor — Sharp text, accurate colors, and enough resolution to have a code editor, tree view, and terminal side by side without squinting.
• Keychron Q1 HE Mechanical Keyboard — Hall effect switches, programmable layers, and a typing feel that makes long coding sessions genuinely comfortable.
• Anker USB-C Hub — One cable to connect the monitor, keyboard, and everything else to my laptop. Clean desk, clean mind.

(Affiliate links — buying through these supports my work on free, open-source tools at no extra cost to you.)

Try It, Break It, Tell Me What’s Missing

JSON Forge is free, open, and built for developers who care about their data. I use it daily — it’s replaced every other JSON tool in my workflow. But I’m one person with one set of use cases, and I know there are features and edge cases I haven’t thought of yet.

Give it a try at orthogonal.info/json-forge. Paste in the gnarliest JSON you’ve got. Try the auto-fix on something that’s almost-but-not-quite valid. Explore the tree view on a deeply nested response. Install it as a PWA and use it offline.

If something breaks, if you want a feature, or if you just want to say hey — I’d love to hear from you. And if JSON Forge saves you even five minutes of frustration, consider buying me a coffee. It keeps the lights on and the tools free. ☕

References

1. Mozilla Developer Network — “Working with JSON”
2. OWASP — “OWASP Top Ten Privacy Risks”
3. RFC Editor — “RFC 8259: The JavaScript Object Notation (JSON) Data Interchange Format”
4. GitHub — “JSON Formatter and Validator”
5. NIST — “Guide to Protecting the Confidentiality of Personally Identifiable Information (PII)”

Frequently Asked Questions