The Problem I Was Tired Of
Let me paint you a picture that I'm sure many of you have experienced.
You're debugging a production API response at 11 PM. The JSON is minified, completely unreadable. You quickly Google "JSON formatter online", paste your payload into the first result you find, and hit Format.
Problem solved, right?
Not quite.
What you probably didn't notice is the tiny network request that tool just made — sending your JSON payload (which might contain API keys, user data, internal IDs, or proprietary business logic) to their backend server.
This happened to me one too many times. So I decided to build the tool I actually wanted to use.
Introducing BestOfTool
BestOfTool is a unified workspace of 15+ JSON utilities that run 100% inside your browser.
Zero server uploads. Zero ads. Zero signup required.
Here is the core principle:
When you paste JSON into BestOfTool, it is parsed by your browser's own JavaScript engine — the same V8 engine that runs your React app locally. The data is processed in memory inside your browser tab and is permanently erased the moment you close it. Our server never sees it.
What Tools Are Available?
Here's the full list of what's currently live at bestoftool.com:
Formatting
JSON Formatter — Beautify minified JSON with 2-space, 4-space, or tab indentation
JSON Minifier — Strip all whitespace to produce the smallest valid JSON payload
JSON Pretty Printer — Human-readable output optimized for documentation
Validation
JSON Validator — Strict RFC 8259 compliance checking with precise error location
JSON Schema Validator — Validate JSON against a custom JSON Schema definition
Conversion
JSON to CSV — Export any JSON array to a clean spreadsheet-ready CSV
CSV to JSON — Import CSVs and convert them to structured JSON instantly
JSON to XML — Convert JSON payloads to XML format for legacy system integrations
XML to JSON — Parse XML documents into modern JSON structures
JSON to YAML — Transform JSON configs to human-friendly YAML
YAML to JSON — Convert YAML back to strict JSON for API use
Analysis
JSON Compare — Deep semantic diff between two JSON objects with highlighted changes
JSON Viewer — Collapsible tree view for exploring deeply nested structures
JSON Diff Viewer — Line-by-line comparison with color-coded additions and removals
JSON Escape / Unescape — Handle special characters in JSON strings
A Real Example: The JSON Compare Tool
One of the most requested tools I built is the JSON Compare feature. Here is a common use case:
You have two versions of an API response and need to know exactly what changed:
Version 1 (old):
json
{
"user": {
"id": 123,
"name": "John Doe",
"role": "viewer"
}
}
Version 2 (new):
json
{
"user": {
"id": 123,
"name": "John Doe",
"role": "admin",
"permissions": ["read", "write", "delete"]
}
}
BestOfTool's compare engine does a semantic diff — it understands the JSON structure rather than just doing a line-by-line text comparison. So it correctly identifies:
✅ role changed from "viewer" to "admin"
✅ permissions is a new field that was added
This is especially useful when comparing Stripe webhook payloads, Kubernetes config files, or MongoDB documents across environments.
Why I Built This Instead of Using Existing Tools
The short answer: none of the existing tools respected my data the way I wanted.
Let me break down my specific frustrations:
Privacy: Most popular JSON formatters have a backend. Your data travels over the network to their server and back. For internal API payloads, this is unacceptable.
Ads: Being interrupted by a full-page popup while debugging at midnight is genuinely infuriating.
Fragmentation: I had 6 different bookmarks for different JSON tools — one for formatting, one for validation, one for comparing, etc. I wanted everything in one place.
Speed: Some tools are genuinely slow. A browser-based tool using native JS APIs is always going to be faster than a round trip to a server.
The Tech Stack (For the Curious)
The entire frontend is built with:
Next.js 14 with App Router
TypeScript — because type safety matters
Tailwind CSS + Shadcn UI for the design system
next-intl for i18n (even though it's English-only right now, future-proofing)
Prisma + PostgreSQL for user accounts and subscription state
Stripe for the premium subscription billing
NextAuth.js for Google / GitHub OAuth
The JSON processing itself uses zero external libraries for the core operations. Native JSON.parse() and JSON.stringify() are faster than you'd think when you let the browser engine handle it.
What's Free vs Premium?
The vast majority of tools are completely free with no login required.
The premium plan ($9.99/month) adds:
Removal of all usage limits on large file processing
JSON Schema Validator (advanced feature)
Priority support
My philosophy: the tool should be so useful for free that paying for premium feels like a natural thank-you.
Try It Out
If you spend any time working with JSON in your daily workflow (and if you're reading Dev.to, you almost certainly do), I'd genuinely love for you to try it out:
👉 bestoftool.com
No signup. No credit card. Just open the tool and start pasting JSON.
I'd Love Your Feedback
I'm actively building this in public. Here is what would help me the most:
What JSON tool is missing? Is there something you do manually every week that I haven't built yet?
What's broken? If you find any bug, please let me know in the comments below.
What format do you wish JSON could convert to? (TOML? SQL? GraphQL schema?)
Drop your thoughts in the comments — I read and respond to everything. 👇
Built by Bibek Bhagat — solo developer shipping tools for the dev community.
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