Free tools that run in your browser
Nothing you type is uploaded, logged or stored. No account, no upload, no server doing the work.
Converters
Unit converter
Length, weight, volume, area, data and speed.
Temperature converter
Celsius, Fahrenheit, Kelvin and Rankine.
Time and duration converter
Milliseconds through to years.
Generators
QR code generator
Links, WiFi details or contact cards, with colors, shaped modules and a center logo.
Hash generator
MD5, SHA-1, SHA-256, SHA-384 and SHA-512, in hex or base64.
Cover image generator
The dark technical-schematic cover this site draws for its own posts -- eyebrow, title, subtitle and a small box-and-arrow diagram.
For developers
Unix timestamp converter
Epoch to date and back, in seconds, milliseconds or microseconds.
Broken image checker
Paste a page's HTML or a list of image URLs and every one is loaded to see whether it still resolves - srcset candidates, lazy-loading attributes and CSS backgrounds included.
Image converter
PNG and JPEG to WebP, in batches, without uploading anything.
Calculators
Percentage calculator
Percentage of, percentage change, and adding or removing a percentage.
Geometry calculator
Area, perimeter, volume and surface area for common shapes.
For WordPress
Serialized PHP repair
Fix plugin and theme settings that vanished after a domain change.
Salt and key generator
The eight wp-config.php security keys, generated in your browser.
.htaccess redirect generator
Escaped, anchored 301 rules from a list of old and new URLs.
Odd and specific
Hyperbolic Time Chamber converter
One day outside is one year inside. Work it out in either direction.
BP to BC converter
Radiocarbon and archaeological dates, handling the missing year zero that most converters get wrong.
Every tool here was rebuilt rather than ported. The originals dated from 2015, and each one keeps its original address so an old link still works.