Small tools that finish the job.
Count words, convert units, check a loan, format JSON, make a password. Twelve working tools on one bench, with no accounts and nothing uploaded.
12 tools · 5 shelves · 0 uploads
The bench: twelve tools, five shelves
Every tool opens in your browser and does one job. Search, pick a shelf, or open one. Nothing you enter is uploaded.
From the workshop
Five short guides on the things these tools are for. Each one links to the tool it explains.
Security
5 min read
Swapping an a for an @ fools nobody. Length and true randomness are what slow an attacker down, and the maths is easy to check.
Money
6 min read
A quote leads with the monthly payment. The interest total, the early-years split and the term you choose matter just as much.
Measuring
5 min read
Exact definitions, quick mental shortcuts, and the same-name units that are different sizes in the US and UK.
Design
5 min read
Low contrast is one of the most common accessibility failures on the web. The test is a single ratio, and fixing a colour usually takes one step.
Code
5 min read
JSON looks like JavaScript, but its rules are stricter. Most parse errors come from the same handful of slips.
Built to be checked
Toolhouse is plain JavaScript in a web page. You can verify what it does.
Runs on your device
Every tool is plain JavaScript in this page. The text you paste, the loan you price and the passwords you make never leave your browser.
Real random
Passwords, UUIDs and dice use the browser’s secure random source, with rejection sampling so no character is more likely than another.
Standard formulas
Loans use the fixed-rate annuity formula. Colour contrast follows WCAG 2.1. Unit factors are the exact international definitions, such as 1 inch = 25.4 mm.
How it works
Open a tool, use it, close it.
Open a tool
Choose a shelf and pick the tool you need. There is no account and no sign-up.
Use it
Paste, type or set your values. Results update in your browser as you go.
Close it
Copy the result and close the tab. Nothing was uploaded, so nothing is left behind.
Questions
Do I need an account?
No. There is no sign-up and no login. Open a tool and use it.
Is anything I enter uploaded?
No. The tools run as JavaScript in your browser. The text you paste, the numbers you enter and the passwords you generate stay on your device.
Are the generated passwords really random?
Passwords, UUIDs and dice use the browser’s secure random source, with rejection sampling so no character is more likely than another.
Which formulas and standards do the tools use?
Loans use the fixed-rate annuity formula. Colour contrast follows WCAG 2.1. Unit factors are the exact international definitions, such as 1 inch = 25.4 mm.
Are the tools free?
Yes. All twelve tools are free to use.
I found a mistake. What should I do?
Please tell us using the contact form below. We fix confirmed errors and update the guide’s date.
Contact
Found a bug, a wrong figure, or a tool you’d like to see? Send a note.