Browser-based · Privacy-first · No sign-up
Online Tools for Developers
16 tools including JSON formatter, Base64 encoder and file hash.
Everything runs locally — your data never leaves the browser.
SEO Meta Checker
Analyze meta tags
Header Analyzer
HTTP response headers
HTML Code Validator
Tag errors & unused CSS
CSS Line Formatter
One line per selector
Base64 Encoder
Encode/decode Base64
Image to Base64
Image → Data URI
Text Hash
SHA-256, MD5, SHA-1
URL Encoder
Encode/decode URLs
JSON Formatter
Format & validate JSON
Character Counter
Characters, words, bytes
Text Diff
Compare differences
Color Converter
HEX, RGB, HSL, Tailwind
UUID Generator
Generate UUID v4
Timestamp Converter
Unix ↔ Date conversion
File Hash Generator/Verifier
SHA-256, MD5 checksum · Integrity check
File Compare
Compare two files
Guides
Developer Guides
In-depth guides covering the principles and practical usage of developer tools
SEO Meta Tags Guide
OG, Twitter Card, structured data
HTTP Headers Guide
CSP, CORS, HSTS, cache strategy
HTML Validation Guide
Tag errors, accessibility, unused CSS
CSS Minification
Internals, Vite/Webpack integration
Base64 Encoding
JWT, Data URI, URL-safe variants
URL Encoding Rules
Double encoding, %20 vs +, multilingual
JSON Data Handling
Syntax, format comparison, parsing errors
Character Counting Guide
Unicode, emoji, platform limits
Diff Algorithms
LCS, Myers, reading Git diff
HEX, RGB & HSL Colors
WCAG accessibility, dark mode
UUID v1 vs v4 vs v7
Version differences, DB performance
Unix Timestamps
Y2K38, timezones, ms vs seconds
File Integrity Verification
SHA-256/MD5 principles, SRI
Quick Start
Which Tool Fits Your Problem?
Start from the problem you are facing, not the tool name.
- An API response arrives as one unreadable line — the JSON Formatter restores indentation and pinpoints syntax errors. New to JSON syntax? Read the JSON data handling guide first.
- You need to confirm a download matches the original — generate a SHA-256 checksum in the File Hash Generator and compare it with the publisher's value. With both files in hand, File Compare is faster.
- Non-ASCII characters break in URL parameters — check encoding state with the URL Encoder. Repeated
%25sequences usually mean double encoding. - You want to inspect a JWT or auth header — decode the payload with the Base64 Encoder. Tokens never leave the browser, so production tokens are safe to inspect.
- A deployed page needs an SEO check — audit meta tags with SEO Meta Check and cache/security headers with the Header Analyzer.
- You need to see what changed between two versions — Text Diff highlights line-level changes visually.
How This Site Handles Your Data
Every tool on Integrity runs entirely inside your browser. File hashing uses the built-in Web Crypto API (crypto.subtle.digest); JSON parsing and encoding conversions use native JavaScript functions. Nothing you type or upload is transmitted — you can verify this yourself in the Network tab of your browser's developer tools, and everything is gone when you close the page.
That principle makes it safe to work with data you would hesitate to paste into an unknown web service: internal API responses, auth tokens, unreleased build artifacts. Project background and quality standards are on the About page; bug reports and feature requests go through the Contact page.