How Parallel Execution Works
When you trigger a test plan or multi-test run, QA.tech schedules tests based on your dependency graph:
With no concurrency limit configured, QA.tech auto-scales to run many tests at the same time. A test plan with 20 independent three-minute tests can finish in roughly three minutes instead of an hour.
Parallel execution respects test dependencies.
Limits control how many tests run at the same time within a single run; they
do not change dependency order.
Configure in the Dashboard
Concurrency limits are configured per environment, not per organization or project. Leave Maximum Concurrent Tests empty for unlimited parallel runs, or enter a positive number to cap concurrency for that environment.1
Open Applications & Envs
Go to Settings → Applications &
Envs and
select the application.
2
Edit an environment
Scroll to Environments, open the hamburger menu on the environment you
want to change, and click Edit.
3
Set Maximum Concurrent Tests
Leave the field empty for unlimited parallel runs, or enter a positive
number to limit concurrency.
4
Save
Click Save to apply the limit to future runs that use that environment.
How Limits Apply During a Run
When a run starts, QA.tech reads the limit from each environment used by tests in that run and applies the most restrictive value:
Tests that exceed the limit are queued, not skipped. QA.tech delays extra tests and starts them as slots open, so the full test plan still completes.
When to Set a Limit
Use Maximum Concurrent Tests when parallel runs could overwhelm the environment you are testing:
Leave the field empty when you want the fastest possible test plan execution and your infrastructure can handle concurrent load.
Maximize Parallelism Without Overloading
Parallel execution speed depends on how tests are structured:- Reduce unnecessary dependencies - Independent tests run at the same time; long dependency chains run one after another. See Test Dependencies.
- Set limits per environment - Use a lower limit on staging and a higher or unlimited limit on dedicated test environments.
- Use Resume From for shared login - Reuse browser state within a chain instead of creating many parallel login tests against the same auth endpoint.
Frequently Asked Questions
Can I set a concurrency limit for my whole organization or project?
Can I set a concurrency limit for my whole organization or project?
No. Limits are configured per environment under Settings → Applications
& Envs. If you need the same cap everywhere, set it on each environment
(staging, production, and so on).
Does a limit of 5 mean only five tests ever run?
Does a limit of 5 mean only five tests ever run?
No. Up to five tests run at the same time for that run. When one finishes,
the next queued test starts. The full plan still runs to completion.
Do dependency chains count as one parallel slot?
Do dependency chains count as one parallel slot?
Each active test uses a slot. Tests in the same chain run one after
another, so they typically use one slot at a time for that chain. Independent
chains each use their own slots up to your limit.
Can I set the limit via API?
Can I set the limit via API?
Not today. Maximum Concurrent Tests is configured in the dashboard on each
environment. Per-run API overrides support environment URLs and device
presets; see Start Run API.
What happens if I leave Maximum Concurrent Tests empty?
What happens if I leave Maximum Concurrent Tests empty?
The environment has no concurrency cap. QA.tech parallelizes independent tests
and scales concurrent agents based on demand.
Related Documentation
- Projects, Applications, Environments - Where environments and URLs are defined
- Test Plans - Group tests and trigger parallel runs
- Test Dependencies - Control order and browser isolation
- Running Tests - Trigger runs from the UI, CI/CD, or schedules