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Fast, private tools for developers

Useful browser-based utilities for code, data, text and web workflows. No upload required.

18focused tools

Local processingRuns in your browser

Private by designYour input stays in this browser.

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18 tools shown

Format & convert

JSON Formatter & Validator

Format, validate and inspect JSON directly in your browser.

Format & convert

JSON to CSV Converter

Turn an array of JSON objects into a spreadsheet-friendly CSV file.

Format & convert

CSV to JSON Converter

Convert comma-separated data into an array of JSON objects.

Encode & decode

JWT Decoder

Inspect the header and payload of a JSON Web Token without sending it anywhere.

Encode & decode

Base64 Encoder & Decoder

Encode text to Base64 or decode Base64 back to UTF-8 text.

Encode & decode

URL Encoder & Decoder

Safely encode query text or decode percent-encoded URLs.

Encode & decode

UUID Generator

Generate random UUID v4 identifiers in your browser.

Time & scheduling

Unix Timestamp Converter

Convert Unix seconds or milliseconds to an ISO date and local time.

Text & testing

Regex Tester

Test a JavaScript regular expression against sample text locally.

Time & scheduling

Cron Expression Explainer

Read the five fields of a standard minute-hour-day-month-week cron expression.

Text & testing

Text Diff Checker

Compare two text blocks line by line in your browser.

Format & convert

SQL Formatter

Add readable line breaks and indentation to common SQL queries.

Encode & decode

Text Hash Fingerprint

Create a fast FNV-1a fingerprint for comparing text samples.

Web utilities

Color Converter

Convert a hex color into RGB, HSL and CSS variable formats.

Encode & decode

HTML Entity Encoder & Decoder

Escape special characters for HTML or decode common entities back to text.

Text & testing

Password Generator

Generate random passwords locally with adjustable length and symbols.

Web utilities

User-Agent Parser

Extract browser, operating system and device hints from a User-Agent string.

Encode & decode

Number Base Converter

Convert binary, octal, decimal and hexadecimal values for coding workflows.

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Developer guides

Understand the boundary behind the output

Detailed workflows for data transformation, encoding and trust, text debugging, time and web interoperability.

Browse all guides

Data transformation10 min read

Reliable JSON and CSV transformation: schemas, quoting and round-trip tests

A conversion is reliable only when the source contract, destination dialect and edge cases are explicit. This guide turns a quick browser conversion into a controlled, testable data handoff.

Encoding and security boundaries11 min read

Encoding, tokens and identifiers: where representation stops and trust begins

Developer incidents often come from assigning security meaning to a representation. This guide separates reversible encoding, random identifiers, cryptographic verification and credential handling.

Text and debugging9 min read

Regex, diff and text debugging: build evidence from minimal fixtures

Text tools are most useful when their algorithm and limits are explicit. This guide separates match evidence, positional changes, formatting and true syntax validation.

Web interoperability10 min read

Time, URLs and web interoperability: test boundaries, not appearances

Web values often look readable while carrying hidden unit, context or compatibility assumptions. This guide traces each value through the system that actually consumes it.