# Testing is single threaded?

**URL:** <https://discourse.julialang.org/t/testing-is-single-threaded/131483>\
**Category:** General Usage\
**Created:** [August 9, 2025, 12:12am UTC](https://discourse.julialang.org/t/testing-is-single-threaded/131483 "2025-08-09T00:12:19Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![freeman](https://avatars.discourse-cdn.com/v4/letter/f/ec9cab/32.png) [@freeman](https://discourse.julialang.org/u/freeman)\
**Post date:** [August 9, 2025, 12:12am UTC](https://discourse.julialang.org/t/testing-is-single-threaded/131483/1 "2025-08-09T00:12:19Z")

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Is testing single threaded?

I just tried `]test` DataFrames.jl and it’s been going for what feels like 20 minutes, but as far as I can tell it uses 1 single core? Surely testing is trivially multi-threaded?

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**Author:** ![jling](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jling/32/212909_2.png) [@jling](https://discourse.julialang.org/u/jling)\
**Post date:** [August 9, 2025, 12:15am UTC](https://discourse.julialang.org/t/testing-is-single-threaded/131483/2 "2025-08-09T00:15:20Z")

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> [@freeman](#):
>
> Surely testing is trivially multi-threaded?

no because the native `@testset` supports dependency that cross different blocks, so it’s in fat not trivial.

One option is to use [Prerelease of new testing framework and test run UI in VS Code](https://discourse.julialang.org/t/prerelease-of-new-testing-framework-and-test-run-ui-in-vs-code/86355)

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**Author:** ![adolgert](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/adolgert/32/20286_2.png) [@adolgert](https://discourse.julialang.org/u/adolgert)\
**Post date:** [August 10, 2025, 2:25pm UTC](https://discourse.julialang.org/t/testing-is-single-threaded/131483/3 "2025-08-10T14:25:42Z")

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Most of the unit testing frameworks support multithreaded testing. It’s part of the reason they exist.

- ReTest.jl
- Jute.jl
- TestItems.jl
- XUnit.jl

The other main feature is the ability to select which tests run and randomize the order of tests or filter tests.

HTH - Drew