A proper toolbox for the web.

Link shorteners, uptime monitors, DNS checkers and palette generators, plus a calculator or two. Pick a tool and get started.

Developer

Sign-in required

API tester

Send requests to any API endpoint and inspect the response

Browser info

See details about the browser and device you're using

Colour converter

Convert colours between hex, RGB, CMYK, HSV and HSL formats

Contrast checker

Check colour contrast against WCAG AA and AAA requirements

Marketing

A/B test calculator

Check if your A/B test result is statistically significant

Ad metrics calculator

Work out CTR, CPC, CPA, ROAS and ROI from your ad numbers

Sign-in required

Link shortener

Shorten long links into short, shareable URLs

Meta tag checker

Check a page's title, description and SEO meta tags

Design

Colour converter

Convert colours between hex, RGB, CMYK, HSV and HSL formats

Colour palette generator

Generate colour palettes from a colour wheel using colour harmonies

Contrast checker

Check colour contrast against WCAG AA and AAA requirements

Favicon generator

Check a site's favicon setup and generate exactly the files needed to fix it

SEO

Favicon generator

Check a site's favicon setup and generate exactly the files needed to fix it

Sign-in required

Link crawler

Crawl your entire site to find broken links fast

Meta tag checker

Check a page's title, description and SEO meta tags

Open Graph checker

Preview how a page looks when shared on social media

Calculators

A/B test calculator

Check if your A/B test result is statistically significant

Ad metrics calculator

Work out CTR, CPC, CPA, ROAS and ROI from your ad numbers

Average calculator

Calculate the mean, median, mode and range of numbers

Calculator

A simple calculator for everyday sums

Text

Encoder / decoder

Encode and decode Base64, URL, JWT, hex and more

Lorem ipsum generator

Generate placeholder text for mockups and layouts

Password generator

Generate a strong, memorable password in seconds

Regex tester

Test regular expressions with live match highlighting

Security

CORS checker

Test how a URL responds to cross-origin requests

Hash generator

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

HTTP header checker

Check the HTTP headers returned by any URL

JWT decoder

Decode JSON Web Tokens, check expiry and verify signatures

Network / domain

Sign-in required

API tester

Send requests to any API endpoint and inspect the response

DNS lookup

Look up DNS records for any hostname

HTTP header checker

Check the HTTP headers returned by any URL

IP address finder

Find your public IPv4 and IPv6 address

Converters

Colour converter

Convert colours between hex, RGB, CMYK, HSV and HSL formats

Encoder / decoder

Encode and decode Base64, URL, JWT, hex and more

Sign-in required

Image converter

Convert images between formats like PNG, JPG and WebP

Unix timestamp converter

Convert Unix timestamps to dates and back, in any time zone

Finance / money

Fuel calculator

Work out how much a trip will cost in fuel

Sign-in required

Income and bills tracker

Track your incomings and outgoings at a glance

Percentage calculator

Work out percentages, discounts and changes fast

Every tool is free to use. Most need no signup. A few, such as the link shortener and uptime monitor, need a free account, and Pro lifts the limits on those.

If you find any of these tools useful – or if you have any suggestions – please let me know.