Troubleshooting and FAQ
Answers to the questions that come up most, grouped by topic.
Privacy and data
Does the app send my text anywhere?
No. Every tool does its work on your device and none of them uses the network. That is the reason to use it for tokens, passwords and work data instead of a website.
What does the app keep?
Only your theme and your favorites. Text you type into a tool, and results such as generated passwords, are gone when you leave that tool.
Why does the Android app ask for the camera?
Only the QR Code Scanner uses the camera, and Android asks the first time you open it. If you refuse, every other tool still works.
Finding tools
A tool is missing from the grid
A filter is probably still active. Clear Search tools… and select All. Search and the category chips apply together, so a search inside the wrong category finds nothing.
"No favorites yet — tap the star on any tool"
You selected Favorites before starring anything. Select All, star a tool with the star on its card, then select Favorites again.
How do I change the theme back?
Press the theme button in the title bar until you reach the one you want. The order is system, light, dark.
JSON
The formatter reports an error but my JSON looks fine
Go to the line and column in the message and look just before that point. The common causes are a trailing comma, single quotes, a key without quotes, or a comment. JSON allows none of these. See Reading an error.
The output is not identical to my input
The Formatter and the Minifier read the data and write it again. The meaning is the same, but spacing, and occasionally the way a number is written, can differ. If an object repeats a key, only the last value is kept.
Encoding and tokens
"Invalid Base64 input"
The text is not valid Base64, or it decodes to data that is not text, such as an image. The tool decodes to text only. Check that you copied the whole value and nothing extra, such as quotes around it.
The JWT Decoder says the token needs three parts
A JWT is three pieces joined by two dots. Copy the token again and leave out anything around it, such as the word Bearer or quotation marks. Some tokens that look similar are not JWTs and cannot be decoded.
The decoder says "✓ valid". Is my token accepted by the server?
Not necessarily. The tool checks only whether the expiry time has passed. It does not verify the signature, so it cannot tell whether a token is genuine or will be accepted.
My hash does not match the one I expected
The tool hashes exactly the text in the box. A space or a line break at the end changes the result completely. Also check that both sides use the same algorithm. To check a downloaded file, use a command-line tool such as sha256sum: this tool hashes text, not files.
Regex and timestamps
My pattern works elsewhere but not here
Type the pattern without surrounding slashes and without flags at the end. Use the three option chips for flags. The syntax is the JavaScript one, so features that exist only in other regex flavours are not available.
The timestamp converts to a date in 1970 or far in the future
The unit was guessed wrongly. Numbers with 13 or more digits are read as milliseconds and shorter ones as seconds. The first line of the result says which was used.
The date I converted is a few hours off
A date without a time zone is read as local time. Add Z at the end to give a UTC time, for example 2026-07-13T14:30:00Z.
QR codes
The QR Code Scanner says camera scanning is not available
The scanner works in the Android app only. On Linux, scan with a phone.
How do I save a QR code?
Take a screenshot. The generator has no save or share button.
My QR code is hard to scan
Shorten the content, increase Size, and make sure there is a clear margin around the code on the screen or on paper.
Installing
Which Android file do I download?
Take developer-toolbox-1.0.0-universal.apk if you are unsure. See Install.
Is there a Windows version?
Release 1.0.0 has Android and Linux (amd64) downloads only.
Get help
Report a problem or ask for a tool on the Developer Toolbox issues page. Say which platform you use and the name of the tool. Remove any real tokens or passwords from what you post.