Dev & Tech Tools

JSON formatters, code beautifiers, encoders, decoders, converters, and everyday utilities built for developers and technical professionals.

Developers spend a surprising amount of time on small utility tasks — formatting a blob of JSON, encoding a string to Base64, converting a timestamp, validating a regex. These are not complex problems, but switching to a terminal or searching for a random tool every time breaks your flow.

Our developer tools are built to be fast, clean, and immediately useful. Paste your input, get your output. No ads covering the text area, no mandatory signups, no "download our desktop app" popups. Just the tool, ready to use.

Everything runs client-side in your browser. Your code and data never leave your machine.

Dev & Tech Tools

AI Token Calculator

Count tokens and estimate API costs for any AI model.

Color Converter & Palette Generator

Convert colors between formats and generate harmonious palettes

Cron Expression Builder

Build and decode cron expressions with a visual schedule editor.

CSS Generator

Generate beautiful CSS gradients, shadows, and glassmorphism effects.

Design Token & Color System Generator

Generate complete design systems from a single brand color

DNS Lookup

Query and inspect all DNS records for any domain instantly

Encoding Toolkit

Encode, decode, and convert between Base64, URL, HTML, and more.

Hash Generator

Generate MD5, SHA-1, SHA-256, and SHA-512 hashes instantly

HTML Cleaner & Formatter

Clean messy HTML from Word, Google Docs, and CMS editors

HTTP Security Header Grader

Audit your HTTP security headers with A-F grades per category

IP Subnet Calculator

Calculate subnet details from any IP/CIDR notation

JSON Formatter & Validator

Format, validate, and explore JSON with instant error detection

JWT Decoder

Decode, inspect, and validate JSON Web Tokens instantly.

Link Building Cost Calculator

Estimate link building costs by DA, niche, and link type

Meta Tag Generator

Generate SEO meta tags, Open Graph, and Twitter Cards with live previews

Password Generator

Generate cryptographically secure passwords with strength analysis

QR Code Generator

Generate customizable QR codes for URLs, WiFi, contacts, and more

Regex Tester

Build and test regular expressions with live match highlighting

Robots.txt Generator

Build and validate robots.txt files visually

SQL Formatter

Format and beautify SQL queries instantly

SQL Query Builder & Explainer

Build SQL visually or paste queries for plain-English explanations

UUID Generator

Generate, validate, and format UUIDs instantly

XML Sitemap Generator

Generate valid XML sitemaps with URL validation and smart splitting

Who Are These Tools For?

Software Developers

Format JSON, encode strings, convert data types, and handle the small utility tasks that come up every day.

DevOps & SREs

Decode tokens, inspect payloads, convert timestamps, and troubleshoot data formats on the fly.

CS Students

Validate JSON, experiment with encodings, and learn data formats with instant visual feedback.

Frequently Asked Questions

No. All developer tools run entirely in your browser using JavaScript. Your data never leaves your device, making these tools safe for use with production data.

We offer ten free developer tools: JSON formatter and validator, Base64 and encoding toolkit, regex tester, color converter and palette generator, UUID generator, hash generator (MD5, SHA-256), cron expression builder, CSS generator, JWT decoder, and AI token cost calculator. All tools run client-side — your data never leaves your browser.

The tools are optimized for typical developer use cases. Very large files (over a few megabytes) may be slow depending on your browser and device. For bulk processing, a local CLI tool is recommended.

Yes. All tools on EvvyTools support dark mode. The theme follows your system preference automatically, or you can toggle it manually using the theme switch in the navigation bar.