# Appachi Tools

> Free online developer tools that run entirely in your browser. No signup, no uploads — the data you paste never leaves your device. Built by Appachi Tech.

Appachi Tools is a collection of fast, privacy-first web utilities for everyday development work. Every tool is free and runs client-side in JavaScript; only the DNS Lookup tool makes a request (to public DNS-over-HTTPS resolvers).

## Formatters & Validators

- [JSON Formatter](https://www.appachi.tech/tools/json-formatter): Format, validate, and beautify JSON instantly.
- [SQL Formatter](https://www.appachi.tech/tools/sql-formatter): Beautify and format SQL queries for readability.

## Encoders & Decoders

- [Base64 Encode / Decode](https://www.appachi.tech/tools/base64): Encode and decode Base64, including URL-safe variant.
- [URL Encode / Decode](https://www.appachi.tech/tools/url-encoder): Percent-encode and decode URLs and query strings.
- [JWT Decoder](https://www.appachi.tech/tools/jwt-decoder): Decode and inspect JSON Web Tokens safely.
- [HTML Entity Encoder](https://www.appachi.tech/tools/html-entities): Encode and decode HTML entities safely.
- [Image to Base64](https://www.appachi.tech/tools/image-base64): Convert images to Base64 data URIs in your browser.

## Converters

- [Epoch Converter](https://www.appachi.tech/tools/epoch-converter): Convert Unix timestamps to dates and back.
- [Color Converter](https://www.appachi.tech/tools/color-converter): Convert colors between HEX, RGB, HSL and HSV.
- [JSON ⇄ YAML](https://www.appachi.tech/tools/json-yaml): Convert between JSON and YAML in one click.
- [Number Base Converter](https://www.appachi.tech/tools/number-base): Convert between binary, octal, decimal and hex.
- [.env ⇄ JSON](https://www.appachi.tech/tools/env-json): Convert between .env files and JSON.
- [JSON ⇄ CSV](https://www.appachi.tech/tools/json-csv): Convert between JSON arrays and CSV in one click.
- [JSON to TypeScript](https://www.appachi.tech/tools/json-typescript): Generate a TypeScript interface from a JSON sample.

## Generators

- [Cron Expression Editor](https://www.appachi.tech/tools/cron): Build and explain crontab schedules in plain English.
- [Hash Generator](https://www.appachi.tech/tools/hash): Generate MD5, SHA-1, SHA-256 and SHA-512 hashes.
- [Password Generator](https://www.appachi.tech/tools/password-generator): Create strong, random passwords with full control.
- [UUID Generator](https://www.appachi.tech/tools/uuid): Generate random UUID/GUID v4 and v7 identifiers.
- [QR Code Generator](https://www.appachi.tech/tools/qr-code): Turn any text or URL into a downloadable QR code.
- [Lorem Ipsum Generator](https://www.appachi.tech/tools/lorem-ipsum): Generate placeholder text by paragraphs, sentences or words.
- [HMAC Generator](https://www.appachi.tech/tools/hmac-generator): Generate a keyed-hash message authentication code.
- [Password Hasher](https://www.appachi.tech/tools/password-hasher): Hash and verify passwords with bcrypt or PBKDF2.

## Text & Code

- [Regex Tester](https://www.appachi.tech/tools/regex-tester): Build and debug regular expressions with live matching.
- [Diff Checker](https://www.appachi.tech/tools/diff): Compare two texts and highlight every difference.
- [Markdown Editor](https://www.appachi.tech/tools/markdown): Write Markdown with an instant live preview.
- [Case Converter](https://www.appachi.tech/tools/case-converter): Convert text between every common case.
- [Word Counter](https://www.appachi.tech/tools/word-counter): Count words, characters, sentences and reading time.
- [Slugify](https://www.appachi.tech/tools/slugify): Turn any text into a clean URL slug.
- [Regex Cheat Sheet](https://www.appachi.tech/tools/regex-cheatsheet): Every common regex token, with a plain-English meaning and example.

## Network

- [DNS Lookup](https://www.appachi.tech/tools/dns-lookup): Look up A, MX, TXT and other DNS records.
- [HTTP Status Codes](https://www.appachi.tech/tools/http-status-codes): Searchable reference for every HTTP status code.
- [CIDR / Subnet Calculator](https://www.appachi.tech/tools/cidr-calculator): Calculate network range, netmask and usable hosts from CIDR notation.

## Design & Visual

- [Open Graph Preview](https://www.appachi.tech/tools/og-preview): Preview and generate the meta tags for how a link looks when shared.
- [Favicon Generator](https://www.appachi.tech/tools/favicon-generator): Generate every favicon size from one image.
- [CSS Gradient Generator](https://www.appachi.tech/tools/css-gradient): Build a linear or radial gradient and copy the CSS.

## Blog

- [Why Appachi Tools Stays Fully Crawlable by AI Assistants](https://www.appachi.tech/blog/why-we-stay-crawlable-by-ai): A growing number of developer-tool sites block scrapers outright, AI crawlers included. We do the opposite on purpose — here's the actual infrastructure behind that decision, not just the pitch.
- [JSON vs. YAML: Same Data, Two Philosophies](https://www.appachi.tech/blog/json-vs-yaml): They describe identical structures, but JSON and YAML optimize for opposite audiences — one for machines, one for humans. That difference explains both YAML's popularity in config files and its most notorious gotcha.
- [Cron Expressions Explained: A Plain-English Guide to `* * * * *`](https://www.appachi.tech/blog/cron-expressions-explained): Five fields, a handful of special characters, and one genuinely surprising gotcha about how day-of-month and day-of-week combine. Everything you need to stop guessing at cron syntax.
- [UUID v4 vs v7: Why Your Database Primary Keys Might Be Slowing You Down](https://www.appachi.tech/blog/uuid-v4-vs-v7): Fully random UUIDs are the safe, boring default — until they become a real, measurable database performance problem at scale. Here's the mechanism, and why UUID v7 exists to fix it.
- [What's Actually Inside a JWT (and What 'Decoding' Really Means)](https://www.appachi.tech/blog/whats-inside-a-jwt): JWTs look encrypted. They're not — by default, anyone can read every field. Here's exactly what a token contains, what the signature does and doesn't protect, and the mistake that follows from misunderstanding it.
- [Encoding vs. Hashing vs. Encryption — and Why Base64 Isn't a Security Feature](https://www.appachi.tech/blog/encoding-vs-hashing-vs-encryption): The three most confused words in developer tooling, untangled: what each one actually does, when to use which, and the mistakes that keep happening because they get mixed up.

## Products

- [Suvadu](https://suvadu.sh): Total recall for your terminal — database-backed shell history.
- [Kaval](https://www.appachi.tech/kaval): Guard your ports — a port and process manager TUI.

## More

- [Privacy Policy](https://www.appachi.tech/privacy)
- [GitHub](https://github.com/AppachiTech)