Every developer has been there. You need to quickly convert an IP address to hex, escape a JSON string, or turn some text into a CSV file. Your options? Install yet another npm package, find a shady website that uploads your data to a server, or write a one-off script.
What if you could do all of that directly in your browser, with zero data leaving your machine?
I built a collection of browser-based developer tools that handle common data format conversions entirely client-side. No server processing, no data uploads, no accounts required. Here's how they solve real problems.
The Problem with Existing Tools
Most online conversion tools have one or more of these issues:
- Privacy risk: Your data gets sent to a server. That JSON payload might contain API keys or PII.
- Slow round-trips: Server processing adds latency, especially for simple transformations.
- Bloated interfaces: You want one thing, but you get popups, ads, and sign-up walls.
Client-side processing eliminates all of these. The data never leaves your browser tab.
7 Conversions Every Developer Needs
1. Text to CSV
Got a block of tab-separated or space-separated data from a log file? Paste it in, configure your delimiter, and get a clean CSV instantly. No more regex gymnastics.
Try it: Text to CSV Converter
2. JSON Escape / Unescape
Working with JSON inside JSON (hello, API gateway configurations)? Properly escaping nested JSON strings is error-prone by hand. The JSON Escape tool handles special characters, unicode, and nested structures correctly every time.
3. IP Address to Hex (and Back)
Network engineers and security researchers frequently need to convert between IP address formats. Whether you're analyzing packet captures or configuring ACLs, the IP to Hex converter and Hex to IP converter make it instant.
4. JSON to YAML
Switching between configuration formats? Kubernetes uses YAML, but your API returns JSON. The JSON to YAML converter handles nested structures, arrays, and multi-line strings without breaking indentation.
5. Base64 Encode/Decode
From debugging JWT tokens to embedding images in CSS, Base64 comes up constantly. The Base64 encoder/decoder supports both text and file inputs.
6. Pantone to Hex
Designers hand you Pantone colors, CSS needs hex values. The Pantone to Hex converter bridges that gap without needing Photoshop open.
7. GraphQL Query Formatter
Messy GraphQL queries from logs or documentation? The GraphQL Formatter cleans up indentation and structure so you can actually read what's being queried.
The Full Toolkit
These are part of a larger set of free, open-source tool sites I've been building:
ToolBox Online — 25 Tools
Code tools, converters, calculators, and generators. Highlights: JSON Escape, Text to CSV, IP to Hex, UUID Generator, Morse Code Translator, Resistor Color Code Calculator.
DevToolKit — 20 Tools
Developer-focused utilities: Cron Expression Generator, Nginx Config Generator, JWT Decoder, Regex Tester, Chmod Calculator, Docker Compose Generator, and 5 hash generators (MD5, SHA-256, SHA-1, SHA-512, Bcrypt).
CalcHub — 28 Calculators
From TikTok Shop Fee Calculator to LLM API Cost Calculator, covering e-commerce fees, finance, and tech calculations.
ImageToolKit — 18 Tools
Image processing entirely in-browser: resize, compress, convert (PNG/JPG/HEIC/AVIF), crop, watermark, QR code generation, and more.
Tech Stack
All sites are built with:
- Next.js 16 (App Router) + React 19 + TypeScript
- Tailwind CSS 4 for styling
- Deployed on Vercel
- Every tool runs 100% client-side
Open Source
All code is available on GitHub:
What data format conversion do you find yourself doing most often? I'm always looking for the next tool to build.
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