Clobbr

See your API's real performance at a glance.

Clobbr hits an endpoint in sequence or in parallel and shows what happens to response times under load. It runs on your machine, on macOS, Windows and the CLI. One lifetime licence. No account.

Go to websiteClobbr at clobbr.appAll products
Percentiles at a glance
p50 / p95 / p99
No account, no upload
Local-first
Licence, not a subscription
Lifetime
The Clobbr homepage. The headline reads “See your API's real performance at a glance” next to a result card showing p50, p95 and p99 response times and a latency chart.
clobbr.appclobbr.app · captured 2026-09-08

What it is

Load testing without the onboarding call

Clobbr answers one question well: how does this endpoint behave when you hit it again and again? Give it a URL. Choose how many calls, and whether they run in sequence or in parallel. It reports what happened to response times.

It reports percentiles. An average hides the thing you are looking for. p95 and p99 are where the timeouts live. Clobbr puts those numbers side by side, so a long tail shows instead of averaging away.

It is local-first. Tests run from your machine against your endpoint. There is no account to create and no results sent to someone else's dashboard. It comes as a desktop app for macOS and Windows and as a CLI for scripting the same check, on a lifetime licence rather than a subscription.

Why it is built this way

The ideas behind it

  1. 01

    Sequential or parallel

    Sequential runs show baseline latency. Parallel runs show what contention does. One toggle switches between them.

  2. 02

    Percentiles, not averages

    p50, p95 and p99 side by side. The mean is where slow requests hide.

  3. 03

    Local-first

    Runs on your machine against your endpoint. No account. No data leaves your laptop.

  4. 04

    App and CLI

    Explore in the app. Then automate the same test from the command line.

Specifics

What you get

  • Load test any REST or GraphQL endpoint, in sequence or in parallel
  • Read p50, p95 and p99 instead of one misleading average
  • Browse result history per endpoint instead of a one-off terminal dump
  • Runs locally on macOS and Windows, or headless through the CLI
  • No account and nothing uploaded. The tests run on your machine.
  • One lifetime licence, not a per-seat subscription

Captured from the live site

What it looks like

Captured from clobbr.app by this site's asset pipeline, with navigation and overlays removed.

The features section of the Clobbr site, headed “Eight primitives. One feedback loop.”, next to a screenshot of the app listing requests to several endpoints with their response times.
Requests and their response timesclobbr.app · captured 2026-09-08

Straight from the source

“See your API’s real performance at a glance.”

Clobbr is a fast, local-first API load testing tool for macOS, Windows, and CLI. Lifetime license, no subscription, no account, GraphQL + REST supported.

Read from clobbr.app on 2026-09-08