All Tools
Every tool on Zentry Tools, grouped by category. Free to use, no sign-up required.
Calculators
Calculator
A fast, safe on-screen calculator for everyday arithmetic.
Age Calculator
Work out an exact age in years, months and days from any birth date.
Percentage Calculator
Calculate percentages, increases, decreases and differences instantly.
Date Difference Calculator
Find the exact number of days, weeks, months and years between two dates.
Unit Converter
Convert length, weight, temperature, area, volume, speed and more.
Text Tools
Encoding & Decoding
Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to readable text.
URL Encoder / Decoder
Encode or decode URLs and URI components safely.
HTML Encoder / Decoder
Convert special characters to and from HTML entities.
JWT Decoder
Inspect a JSON Web Token's header and payload in your browser.
Hash Generator
Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes from text.
Image Tools
Image Compressor
Shrink JPG, PNG and WebP images without uploading them anywhere.
Image Resizer
Resize images to exact dimensions or by percentage.
Image Converter
Convert images between JPG, PNG and WebP formats.
Image Cropper
Crop, rotate and flip images with common aspect ratio presets.