zerouploads

Developer Tools

11 developer tools. Format, encode, hash and read tokens for everyday API jobs. Pasted secrets stay put.

Paste something to start

we name it, you pick the tool

nothing is parsed until you open a tool

All developer tools

14 tools · 4 groups · 11 ready

JSON & data

4

Encode & decode

5

Hash & tokens

3

Inspect & compare

2

About these developer tools

The reason to run these locally is what you paste into them. A JWT carries a session. A JSON blob from a bug report carries customer records. A tool that uploads them sends both to someone else's server.

Everything here happens in the page. Hashing uses the browser's own crypto, except for MD5, which the page computes itself. Base64 and URL encoding use small codecs written for this site, and JSON is read by the parser already in your browser. There is no request to inspect, because there is no request.

A JWT is decoded first. For an HMAC token, you can enter its signing secret to check the signature in this tab. Public-key signatures are read but not verified.

Crypto
SHA-1, SHA-256, SHA-384 and SHA-512 from the browser itself.
Tokens
JWTs are decoded locally. HMAC signatures can be checked with a secret you provide.
Size
No paste limit beyond what the tab can hold.
Logs
None. Nothing reaches a server to be logged.

Frequently asked questions

Is my paste sent anywhere?
No. It is read in the page by your own browser. That is the whole reason to use a local tool for a token or a customer record.
Do you verify a JWT signature?
HMAC signatures can be checked when you provide the signing secret. The check stays in this tab. Public-key signatures are decoded but not verified.
Is MD5 safe to use?
Not for security. It is fine as a checksum for matching a file against a published hash. Use SHA-256 for anything that matters.
Why did Base64 make my file bigger?
Base64 spends four characters on every three bytes, so it grows by about a third. It is for carrying binary through text, not for saving space.
Can I paste something confidential?
That is the point. Nothing is transmitted or stored, and the page works with the network off, which you can check for yourself.
Is there a size limit?
None that we set. A very large paste is limited by the memory your tab has, and a phone runs out sooner than a laptop.

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