4xx Client Error

The server couldn't even parse what you sent.

Who are you? Please identify yourself.

Reserved for a future where HTTP knows about money. We're not there yet.

We know who you are. The answer is still no.

Nothing here. Never was, or isn't anymore.

That verb doesn't work here.

The server can't serve the format you're asking for.

The proxy in the middle needs you to log in first.

You took too long. The server gave up waiting.

Your request collides with the current state of things.

It existed. It doesn't anymore. This is final.

Send a Content-Length header — the server won't guess.

The conditions you set weren't met — request aborted.

Your payload is bigger than we're willing to accept.

Your URL is longer than the server is willing to parse.

Wrong content type — the server can't process what you sent.

The range you requested doesn't fit within the resource.

The server can't meet the expectation you declared.

Brewing coffee is outside the scope of this service.

You sent this to the right address, but the wrong server.

The request arrived fine. The data inside it didn't make sense.

This resource is locked. Come back later.

A previous step in the batch failed, so this one can't proceed.

Don't replay this — it might not be safe.

This protocol version won't cut it — please upgrade.

You need to send a precondition header — we won't update blindly.

Slow down — you're being rate limited.

Your headers are too heavy. Trim them down.

This content can't be shown here, by law.