Encoding & Data Tools
Nine tools for data rather than prose — formatting, encoding, hashing and generating. Everything runs in your browser, so nothing you paste is uploaded.
Encoding, hashing and encrypting are three different things
They get used interchangeably and they are not remotely the same. Encoding is reversible by design and offers no protection — the Base64 Converter and the URL Encoder exist to make data survive a transport layer, not to hide it. Hashing is deliberately one-way: the Hash Generator produces a fixed-length digest you can compare but never reverse, which is why hashes verify downloads and store passwords. Encryption is reversible with a key, and none of these tools do it. Treating Base64 as security is a genuine and common mistake.
Formatting JSON is really validating it
The JSON Formatter indents and colours a payload, but its more useful job is refusing to. If it cannot parse your text, you have a trailing comma, a single quote where a double belongs, or an unescaped character — and it will point at the position. Paste API responses through it before debugging anything further up the stack.
Unique identifiers and unguessable ones
A UUID from the UUID Generator is unique, not secret: version 4 draws 122 random bits, so collisions are effectively impossible, but a UUID is fine to expose in a URL and useless as a credential. A password from the Password Generator is the opposite — it needs to resist guessing, which comes from length far more than from symbol substitution. Both generate locally in your browser using the platform crypto API, so nothing is transmitted.
Converting between representations
The rest of the set moves one value between formats. The Timestamp Converter turns a Unix epoch into a readable date and back, which is the fastest way to read a log line. The Color Converter moves between HEX, RGB and HSL — HSL being the one worth learning, because adjusting a hue or lightness by hand is trivial in HSL and guesswork in HEX. The QR Generator encodes a URL or string into a scannable image, rendered client-side.
Frequently asked questions
What is the difference between encoding, hashing and encrypting?＋
Encoding changes the representation of data so it survives a channel, and anyone can reverse it — it offers no secrecy. Hashing produces a fixed-length fingerprint that cannot be reversed at all, useful for checking integrity. Encrypting makes data unreadable to anyone without the key, and is reversible only with it. Treating Base64 as security is a genuinely common and serious mistake.
Why does Base64 make my data larger?＋
Because it represents three bytes of input using four characters of output, an increase of about a third. That is the cost of restricting the output to a small set of characters that survive systems which would otherwise mangle arbitrary bytes — email bodies, URLs and JSON strings among them.
Is a UUID guaranteed to be unique?＋
Not guaranteed, but the probability of a collision is so small it can be disregarded in practice. A version 4 UUID draws 122 random bits, and you would need to generate billions before a repeat became remotely likely. The important caveat is that random UUIDs are unpredictable but not secret — never use one as an access token.
Which hash should I use?＋
SHA-256 for anything current. MD5 and SHA-1 are both broken for security purposes — deliberate collisions can be constructed — and survive only as fast checksums against accidental corruption. Note that no general-purpose hash is appropriate for storing passwords; that needs a deliberately slow algorithm designed for the job.