A growing collection of fast, free developer tools that run entirely in your browser. Format JSON, encode Base64, generate UUIDs, and more — with zero server round-trips and no data collection.
JSON is the standard data format for APIs, configuration files, and data exchange. Our JSON tools let you format, beautify, validate, and minify JSON instantly — all processing happens in your browser. Whether you are debugging an API response or preparing data for production, these tools handle it in milliseconds.
Format, beautify, and validate JSON instantly
Use tool →Beautify and pretty-print JSON with custom indentation
Use tool →Validate JSON syntax with detailed error reporting
Use tool →Minify JSON by removing all whitespace
Use tool →Encoding converts data between formats for safe transmission across systems. Base64 encoding lets you embed binary data in text channels like JSON and HTML. URL encoding ensures special characters in URLs are transmitted correctly. Our encoding tools support full Unicode and process everything client-side.
Encode and decode Base64 with Unicode support
Use tool →Encode and decode URLs and query parameters
Use tool →Generate unique identifiers for databases, APIs, and distributed systems. Our UUID generator supports versions 1, 4, and 7 with cryptographically secure random number generation via the Web Crypto API. Bulk generation, format options, and UUID validation are all included.
View all generator tools →Most online developer tools send your data to a server for processing. That means your JSON payloads, encoded strings, and generated identifiers pass through someone else's infrastructure. For developers working with sensitive data — API keys in configuration files, authentication tokens, proprietary data structures — this is a real concern.
Client-side tools eliminate this risk entirely. Every tool on CodePersia runs JavaScript in your browser. Your data never leaves your machine. You can verify this by opening your browser's Network tab while using any tool — you will see zero requests containing your input data.
Beyond privacy, client-side processing is faster. There is no network latency, no server queue, no cold starts. Formatting a JSON payload happens in under 10 milliseconds. Generating 100 UUIDs is instantaneous. This speed comes from running native JavaScript in your browser rather than making a round-trip to a remote server.
Client-side tools also have no usage limits. Since there is no server to overload, you can process as much data as your browser can handle. No rate limits, no daily caps, no "upgrade to pro for unlimited usage" prompts. The tools work the same whether you use them once or a thousand times a day.
CodePersia exists because we got tired of online tools that require signups, show intrusive ads, or quietly send data to their servers. We wanted tools that respect the developer workflow: paste, process, copy, done.
Every tool is designed with a dark mode default, monospace fonts for code content, keyboard accessibility, and instant copy buttons on every output. The interface is intentionally minimal — no popups, no email gates, no dark patterns. You use the tool, you get your result, you move on.
This site is sustained by minimal, non-intrusive advertising. We will never gate tool functionality behind a paywall or require an account. If a tool works today, it will work the same way tomorrow.
Many popular online developer tools were built years ago with server-side processing models. They require your data to make a round-trip to their servers, introducing latency and privacy concerns. Some require accounts, limit free usage, or show aggressive advertising that interferes with the developer experience.
CodePersia takes a different approach. By processing everything in the browser, we eliminate the server entirely for tool functionality. This means faster results, complete data privacy, no usage limits, and a cleaner interface. The modern Web Crypto API provides cryptographically secure random generation. TextEncoder and TextDecoder handle full Unicode correctly. The browser is now powerful enough to handle everything these tools need.
We also invest in developer experience: dark mode that actually works, monospace fonts that are pleasant to read, instant feedback on every interaction, and a consistent layout across all tools so there is zero learning curve when you try a new one.
Format, beautify, and validate JSON instantly
Use tool →Beautify and pretty-print JSON with custom indentation
Use tool →Validate JSON syntax with detailed error reporting
Use tool →Minify JSON by removing all whitespace
Use tool →Encode and decode Base64 with Unicode support
Use tool →Encode and decode URLs and query parameters
Use tool →Generate UUID v1, v4, and v7 identifiers
Use tool →Generate GUIDs for .NET, C#, and Microsoft platforms
Use tool →