Performance testing tools for JMeter, k6 and Gatling
Turn a browser recording into a runnable script, convert between all three tools in any direction, read a results file, or check what a script is about to leak. All free, all in your browser — your script is never uploaded.
Free in the browser first. Paid tools and fixed-price migration when the file is too messy for a converter.
Start with the thing that's broken
Three jobs that normally mean installing something, uploading something, or opening a GUI you were trying to avoid. Each one runs in the tab.
Turn a HAR recording into a JMeter test plan
Record a journey in Chrome DevTools, save the HAR, get a runnable JMeter test plan back. A HAR holds every header and cookie of a real session, which is why this one never uploads it.
Open itNeed correlation and k6/Gatling out as well? Perf Script Studio — £99
Performance Tools
Paid tools for the jobs the free converters start — editing JMX without the GUI, reporting at scale, linting scripts, containers, monitoring.
Same job — finished properly
The browser tools are for a clean file and a quick answer. When the recording needs real correlation, you are converting a suite, or you want someone else to own the messy middle, pick one path:
Perf Script Studio — £99
HAR or existing script in → runnable JMeter, k6 or Gatling out, offline. One-time licence.
View productFixed-price migration — from £250
You send sanitised scripts. I convert them in working days. No discovery call, no day rate.
See tiersOr I'll migrate them for you
Fixed price, agreed before anything starts, delivered in working days — with everything that still needs a human listed and explained.
Conversion review
£250
1 working day
One script, any size
Single script
£750
3 working days
Up to 50 HTTP requests and 10 manual-work items
Suite
£1,500
5 working days
Up to 200 HTTP requests and 30 manual-work items
Larger migrations
From £3,000
Agreed with you
No cap — scope agreed up front
Try it on a file you already have
A recording, a test plan, or a results file you have never been able to open without the GUI. It converts in the browser tab — the page cannot make a network call, so nothing you drop on it is uploaded anywhere.
Already know you need the full pipeline? Perf Script Studio · Fixed-price migration