Zappilly

Free Browser-Based Developer Tools for JSON, CSV and XML Processing

Your data. Never leaves your browser.

A fast, private workspace for developers and data teams. Transform JSON, CSV, XML, and more — all processed locally.

Browser-only Instant No signup Free forever

Verify it: open DevTools → Network tab → use any tool → see zero requests.

ENCODE Tools

Base64 Encode/Decode

encode

Encode and decode Base64 data instantly in your browser. A free, secure tool for developers that processes everything locally with no server uploads.

URL Encode/Decode

encode

URL Encode and Decode strings instantly. A free, secure developer tool for processing query parameters and URIs locally in your browser.

CSV Tools

CSV Duplicate Remover

csv

Remove duplicate rows from CSV files securely in your browser. Free online deduplication tool that works locally to ensure your data stays private.

CONVERT Tools

CSV to JSON Converter

convert

Convert CSV to JSON format instantly. A free, private tool for developers that transforms tabular data into JSON arrays locally in your browser.

JSON to CSV Converter

convert

Convert JSON to CSV format instantly in your browser. A free, secure tool that handles nested objects locally with no server uploads. Fast and private.

JSON to Excel Converter

convert

Convert JSON arrays to Excel (XLSX) format securely. A free, browser-based tool for analysts to export JSON data to spreadsheets without server uploads.

XML to CSV Converter

convert

Convert XML to CSV format instantly. A free, secure tool that transforms XML nodes into tabular data locally in your browser for easy spreadsheet analysis.

XML to JSON Converter

convert

Convert XML to JSON format instantly. A free, private developer tool that translates XML documents into JavaScript objects securely in your browser.

JSON Tools

JSON Flattener

json

Flatten nested JSON objects into a single-level structure instantly. Secure, browser-based JSON flattener for easier data analysis and CSV conversion.

JSON Formatter & Validator

json

Format, beautify, and validate JSON data securely in your browser. A free developer tool with syntax highlighting that never uploads your data.

XML Tools

XML Formatter & Validator

xml

Format and beautify XML data securely in your browser. Free online XML formatter that indents code locally with syntax highlighting and zero server uploads.

A colleague got fired for using a tool like this.

He pasted an API response into a random formatter on a Monday morning. The tool logged it. IT found it three weeks later. He was let go that afternoon.

That's why every tool here runs inside your browser. Nothing is ever sent to a server. Here's our guarantee:

Zero Server Processing

When you click "Transform", the computation happens directly on your machine using JavaScript and WebAssembly. No files are ever uploaded.

Zero Data Retention

Because no data touches a server, there are no databases, no logs, and no "delete after 24 hours" promises. Once you close the tab, your data is gone forever.