The tool comes first
You arrived looking for one number or one answer. It is at the top of the page, working, before any explanation. The writing underneath is there if you want it.
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A set of free tools that open, do one job, and get out of the way
No accounts. No installs. No tracking. 443 small tools that load, answer the question you came with, and explain themselves if you want to know more.
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What this is
Twoodo is a library of small web tools: unit converters, device testers, connection speed checks, counters and a few questionnaires. Each one does a single job and nothing else.
Most people arrive from a search for one specific thing — how many pounds are in fifteen kilograms, or whether their microphone is actually working. So the tool you came for is the first thing on the page, above the explanation rather than below it.
Six things this site tries to get right
Show the working
An answer you cannot check is worth less than one you can. Every converter shows where its factor comes from and how the arithmetic goes, updating as you type.
Say what a tool cannot do
A browser cannot benchmark your hard drive or see how much RAM you have. The pages that get asked to do those things say so plainly instead of inventing a number.
Two answers where there are two
A gallon, an ounce, a ton and a cup all mean more than one thing. Those pages give you a switch and an explanation, rather than quietly picking one and hoping.
Nothing is collected
No accounts, no email addresses, no analytics on what you converted. The site is static files; there is no database to put anything in.
It should work on what you have
Phone, old laptop, slow connection, screen reader, dark room. Every page is checked for contrast in both themes and for overflow at 390 pixels wide.
Proof, rather than a promise
Every site claims to respect your privacy. Here is what this page actually requested from the network since it started loading, read from your own browser. Nothing is hidden from this list, including anything awkward.
What this page loaded
live from your browser
How a tool gets made
- 1
Find what people actually search
Not what is tidy to build. The volume section has seventy-one pages because people look up cups, gallons and millilitres constantly, in every combination.
- 2
Build the tool so it works while you type
Two boxes, both live, both directions. No convert button to press, and the address bar keeps your value so the result can be shared.
- 3
Check the number against a definition
A pound is exactly 0.45359237 kilograms because a treaty says so. Wherever an exact definition exists, that is the figure used, and the page says where it comes from.
- 4
Write the part that explains it
Why hexadecimal exists. Why the Imperial fluid ounce is smaller although the Imperial gallon is bigger. Why a stuck pixel is not a dead one. This is the slow part.
- 5
Verify it, then verify the page
Every conversion is checked against independently computed values. Every page is checked for colour contrast in light and dark, and for horizontal overflow on a narrow phone.
What is in the library
- Convert units276
- Test your device41
- Measure and count126
Finding something
Search from the box on the home page, browse the full list by category on the tools page, or press / anywhere on the site to open search from wherever you are.
If a tool gives an answer you think is wrong, or there is a conversion you keep looking up and cannot find here, say so. Both are useful to hear about, and the second one is how most of these got built.
About this domain
Twoodo.com was previously used by a different company for an unrelated product. The domain was acquired and this collection of tools built on it. Nothing here is connected to that earlier business, and its content is no longer published.