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Free API Today

mempool.space API

Bitcoin fees, blocks, transactions and addresses.
Status
Working
API key
Not needed
Browser calls
Runs in the browser
Latency
396 ms
Docs
mempool.space ↗

Build snapshot, not live. One verifier run on , from the machine that built this site. How we check

Example request

GEThttps://mempool.space/api/v1/fees/recommended

Sent from your browser straight to mempool.space. No proxy: this site never sees the request or the answer.

Copy the request

Shell
curl -s 'https://mempool.space/api/v1/fees/recommended'

Response stored by the verifier

This is what mempool.space answered when the verifier sent the request above on : HTTP 200, application/json. Arrays are cut to two items and long strings are shortened. It comes from the build snapshot.

application/json · stored
{
  "fastestFee": 2,
  "halfHourFee": 2,
  "hourFee": 1,
  "economyFee": 1,
  "minimumFee": 1
}

Availability

Up 1 of 1 day checked · 30-day window

What counts as up for this API: an answer within five seconds, a 2xx status, and the JSON body must contain the field "fastestFee".

Last check: — passed, HTTP 200 in 396 ms.

The check runs from our infrastructure, not from where you are. If you need certainty, send the request yourself above. How the verifier works.

Questions

Does the mempool.space API need an API key?

No. The sample request on this page was answered without a key, token or account.

Can I call the mempool.space API from the browser?

Yes. mempool.space answered our verifier with an Access-Control-Allow-Origin header on Oct 3, 2026, so a fetch call from a web page can read the response.

Is the mempool.space API working?

At the check on Oct 3, 2026 it returned HTTP 200 with the expected data in 396 ms. The status at the top of this page shows the most recent result we have.