PyPI · #1189 most downloaded on PyPI

locust

2.46.79.9M downloads/molocustio/locust ↗New releases in your daily digest, changelog included.

Developer-friendly load testing framework

Last release today
04 Oct 2026
Ships on a steady schedule
a new release about every 2 weeks
Nearly every release is documented
notes for 60 of the last 60 stable releases
1 version withdrawn
withdrawn after publishing
6 years old
1050 releases · first in 2020

Release timeline

1050 releases since 2020

2020202120222023202420252026

20202026

One column per quarter.

Releases

2.18.1.dev1031 Oct 2023pre-release
Nothing published for this version
2.18.1.dev427 Oct 2023pre-release
Nothing published for this version
2.18.027 Oct 2023
Make FastHttpUser use requests encoding detection by @cyberw in https://github.com/locustio/locust/pull/2416
What's Changed

Make FastHttpUser use requests encoding detection by @cyberw in https://github.com/locustio/locust/pull/2416

Add a modern web UI based on React, MaterialUI and Vite by @andrewbaldwin44 in https://github.com/locustio/locust/pull/2405

Add run_single_user to __all__ variable by @tdadela in https://github.com/locustio/locust/pull/2417

Modernize the report.html when using the --modern-ui Flag by @andrewbaldwin44 in https://github.com/locustio/locust/pull/2420

Stop supporting Python 3.7 by @cyberw in https://github.com/locustio/locust/pull/2421

Fix too long first wait time for constant_pacing (and constant_throughput) by @cyberw in https://github.com/locustio/locust/pull/2428

refactor(MasterRunner): simplify condition in check_stopped by @tdadela in https://github.com/locustio/locust/pull/2432

New Contributors

@andrewbaldwin44 made their first contribution in https://github.com/locustio/locust/pull/2405

@tdadela made their first contribution in https://github.com/locustio/locust/pull/2417

@singingwolfboy made their first contribution in https://github.com/locustio/locust/pull/2423

Full Changelog: https://github.com/locustio/locust/compare/2.17.0...2.18.0

Additional notes

Add a modern web UI based on React, MaterialUI and Vite (activated using --modern-ui) https://github.com/locustio/locust/pull/2405
Stop supporting Python 3.7 https://github.com/locustio/locust/pull/2421
Fix too long first wait time for constant_pacing (and constant_throughput) https://github.com/locustio/locust/pull/2428

Open source →

2.17.1.dev6526 Oct 2023pre-release

Nothing published for this version

2.17.1.dev6222 Oct 2023pre-release

Nothing published for this version

2.17.1.dev6019 Oct 2023pre-release

Nothing published for this version

2.17.1.dev5815 Oct 2023pre-release

Nothing published for this version

2.17.1.dev5313 Oct 2023pre-release

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2.17.1.dev4211 Oct 2023pre-release

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2.17.1.dev57 Oct 2023pre-release

Nothing published for this version

2.17.05 Oct 2023Deprecated

Log a deprecation warning in Python 3.7 by @cyberw in https://github.com/locustio/locust/pull/2403

What's Changed

Respect hard limit when setting open file limit (NOFILE) by @benofbrown in https://github.com/locustio/locust/pull/2386
chore: bump dockerfile to 3.11-slim base image by @vejmoj1 in https://github.com/locustio/locust/pull/2388
Support user abstract load shape base classes by @noirbizarre in https://github.com/locustio/locust/pull/2393
Allow LoadTestShapes to reuse run-time, spawn-rate and users parameters by @noirbizarre in https://github.com/locustio/locust/pull/2395
Catch exceptions in on_stop by @cyberw in https://github.com/locustio/locust/pull/2402
Log a deprecation warning in Python 3.7 by @cyberw in https://github.com/locustio/locust/pull/2403
Improve performance for statistics handling by @cyberw in https://github.com/locustio/locust/pull/2410
Test and explicitly support Python 3.12 by @cyberw in https://github.com/locustio/locust/pull/2411

New Contributors

@benofbrown made their first contribution in https://github.com/locustio/locust/pull/2386
@vejmoj1 made their first contribution in https://github.com/locustio/locust/pull/2388
@noirbizarre made their first contribution in https://github.com/locustio/locust/pull/2393

Full Changelog: https://github.com/locustio/locust/compare/2.16.1...2.17.0

Open source →

Additional notes

Support user abstract load shape base classes https://github.com/locustio/locust/pull/2393
Allow LoadShapes to reuse run-time, spawn-rate and users parameters https://github.com/locustio/locust/pull/2395
Improve performance for statistics handling https://github.com/locustio/locust/pull/2410
Test and explicitly support Python 3.12 https://github.com/locustio/locust/pull/2411

Open source →

2.16.2.dev3630 Sept 2023pre-release

Nothing published for this version

2.16.2.dev1621 Sept 2023pre-release

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2.16.2.dev1421 Sept 2023pre-release

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2.16.2.dev1215 Sept 2023pre-release

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2.16.2.dev1011 Sept 2023pre-release

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2.16.2.dev830 Aug 2023pre-release

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2.16.2.dev329 Aug 2023pre-release

Nothing published for this version

2.16.15 Aug 2023Deprecated

Deprecate LOCUST_PLAYWRIGHT env var by @cyberw in https://github.com/locustio/locust/pull/2378

What's Changed

Deprecate LOCUST_PLAYWRIGHT env var by @cyberw in https://github.com/locustio/locust/pull/2378
Import locust_plugins if available to give access to its custom arguments by @cyberw in https://github.com/locustio/locust/pull/2379
Delay importing locust-plugins to prevent circular import by @cyberw in https://github.com/locustio/locust/pull/2380

Full Changelog: https://github.com/locustio/locust/compare/2.16.0...2.16.1

Open source →

Additional notes

Deprecate LOCUST_PLAYWRIGHT env var https://github.com/locustio/locust/pull/2378
Import locust_plugins if available to give access to its custom command line arguments https://github.com/locustio/locust/pull/2379

Open source →

2.16.1.dev75 Aug 2023pre-release

Nothing published for this version

2.16.1.dev55 Aug 2023pre-release

Nothing published for this version

2.16.1.dev35 Aug 2023pre-release

Nothing published for this version

2.16.04 Aug 2023

Fix: show host url by @zifter in https://github.com/locustio/locust/pull/2324

What's Changed

Fix: show host url by @zifter in https://github.com/locustio/locust/pull/2324
Rename link text on README.md by @JE-Chen in https://github.com/locustio/locust/pull/2334
Remove codecov from build by @cyberw in https://github.com/locustio/locust/pull/2337
Put dependencies/project information in pyproject.toml instead of setup.cfg (PEP621) by @JE-Chen in https://github.com/locustio/locust/pull/2336
Add worker_connect event by @cyberw in https://github.com/locustio/locust/pull/2344
Duplicated titles by @Daemo00 in https://github.com/locustio/locust/pull/2346
Update rest.py by @BhattcharyaCodes in https://github.com/locustio/locust/pull/2352
Fixed the users dispatching when it got infinite loop (fixes #2345) by @EzR1d3r in https://github.com/locustio/locust/pull/2350
Clarify documentation string for total_content_length by @johenning in https://github.com/locustio/locust/pull/2354
Allow selecting user classes using LOCUST_USER_CLASSES env var by @ibarbech in https://github.com/locustio/locust/pull/2355
Fix passing host to user class when debugging by @LKajan in https://github.com/locustio/locust/pull/2365
Web UI dropdown for custom args with choices by @ktrnka in https://github.com/locustio/locust/pull/2372
update links to requests homepage by @evgeni in https://github.com/locustio/locust/pull/2373
Fix #1910 KeyboardInterrupt with load shapes by @JevonCowell in https://github.com/locustio/locust/pull/2375

New Contributors

@JE-Chen made their first contribution in https://github.com/locustio/locust/pull/2334
@Daemo00 made their first contribution in https://github.com/locustio/locust/pull/2346
@BhattcharyaCodes made their first contribution in https://github.com/locustio/locust/pull/2352
@johenning made their first contribution in https://github.com/locustio/locust/pull/2354
@ibarbech made their first contribution in https://github.com/locustio/locust/pull/2355
@LKajan made their first contribution in https://github.com/locustio/locust/pull/2365
@ktrnka made their first contribution in https://github.com/locustio/locust/pull/2372
@evgeni made their first contribution in https://github.com/locustio/locust/pull/2373
@JevonCowell made their first contribution in https://github.com/locustio/locust/pull/2375

Full Changelog: https://github.com/locustio/locust/compare/2.15.1...2.16.0

Open source →

Additional notes

Add worker_connect event https://github.com/locustio/locust/pull/2344
Allow selecting user classes using LOCUST_USER_CLASSES env var https://github.com/locustio/locust/pull/2355
Web UI dropdown for custom args with choices https://github.com/locustio/locust/pull/2372
Various minor fixes

Open source →

2.15.2.dev484 Aug 2023pre-release

Nothing published for this version

2.15.2.dev474 Aug 2023pre-release

Nothing published for this version

2.15.2.dev3725 Jul 2023pre-release

Nothing published for this version

2.15.2.dev3518 Jul 2023pre-release

Nothing published for this version

2.15.2.dev2726 Jun 2023pre-release

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2.15.2.dev247 Jun 2023pre-release

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2.15.2.dev2131 May 2023pre-release

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2.15.2.dev1929 May 2023pre-release

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2.15.2.dev1724 May 2023pre-release

Nothing published for this version

2.15.2.dev1517 May 2023pre-release

Nothing published for this version

2.15.2.dev1215 May 2023pre-release

Nothing published for this version

2.15.2.dev420 Mar 2023pre-release

Nothing published for this version

2.15.114 Mar 20232 sources agree

Add PERCENTILES_TO_CHART param in stats.py to make the Response Time Chart configurable by @A1BOCO in https://github.com/locustio/locust/pull/2313

What's Changed

Add PERCENTILES_TO_CHART param in stats.py to make the Response Time Chart configurable by @A1BOCO in https://github.com/locustio/locust/pull/2313
Update helper text by @rafaelhdr in https://github.com/locustio/locust/pull/2317

New Contributors

@A1BOCO made their first contribution in https://github.com/locustio/locust/pull/2313
@rafaelhdr made their first contribution in https://github.com/locustio/locust/pull/2317

Full Changelog: https://github.com/locustio/locust/compare/2.15.0...2.15.1

Open source →

2.15.1.dev1014 Mar 2023pre-release

Nothing published for this version

2.15.028 Feb 2023

add is_secret option for custom args to be shown in the web UI masked by @mzhukovs in https://github.com/locustio/locust/pull/2284

What's Changed

add is_secret option for custom args to be shown in the web UI masked by @mzhukovs in https://github.com/locustio/locust/pull/2284
add events when initialize Environment by @keegoo in https://github.com/locustio/locust/pull/2285
docs (#2188): Add Locust Kubernetes Operator by @AbdelrhmanHamouda in https://github.com/locustio/locust/pull/2288
Update performance estimates for modern Python and hardware by @cyberw in https://github.com/locustio/locust/pull/2295
fix: docs describing running without web UI had improper flag -f. Cor… by @adriangonciarz in https://github.com/locustio/locust/pull/2297
Remove verbose FastHttpUser error messages by @cyberw in https://github.com/locustio/locust/pull/2301
Prevent Download as PNG text from getting cut off by @allison-strandberg in https://github.com/locustio/locust/pull/2308
Fix locustio/locust#2302 unknown worker spawning message by @ykvch in https://github.com/locustio/locust/pull/2309
Remove request_success and request_failure event handlers by @cyberw in https://github.com/locustio/locust/pull/2306

New Contributors

@mzhukovs made their first contribution in https://github.com/locustio/locust/pull/2284
@keegoo made their first contribution in https://github.com/locustio/locust/pull/2285
@AbdelrhmanHamouda made their first contribution in https://github.com/locustio/locust/pull/2288
@adriangonciarz made their first contribution in https://github.com/locustio/locust/pull/2297
@allison-strandberg made their first contribution in https://github.com/locustio/locust/pull/2308
@ykvch made their first contribution in https://github.com/locustio/locust/pull/2309

Full Changelog: https://github.com/locustio/locust/compare/2.14.2...2.15.0

Open source →

Additional notes

Add is_secret option for custom args to be shown in the web UI masked https://github.com/locustio/locust/pull/2284
Breaking change: Remove deprecated request_success and request_failure event handlers (unified request handler was introduced in 1.5) https://github.com/locustio/locust/pull/2306

Open source →

2.14.3.dev2927 Feb 2023pre-release

Nothing published for this version

2.14.3.dev2727 Feb 2023pre-release

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2.14.3.dev2526 Feb 2023pre-release

Nothing published for this version

2.14.3.dev2323 Feb 2023pre-release

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2.14.3.dev1329 Jan 2023pre-release

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2.14.3.dev1116 Jan 2023pre-release

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2.14.3.dev911 Jan 2023pre-release

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2.14.3.dev711 Jan 2023pre-release

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2.14.24 Jan 20232 sources agree

Re-add py.typed marker file to package (it was missing in 2.14.1) #2282

Full Changelog: https://github.com/locustio/locust/compare/2.14.1...2.14.2

Open source →

2.14.13 Jan 2023Deprecated

Fix setuptools deprecation warnings by @heyman in https://github.com/locustio/locust/pull/2281

What's Changed

remove typo in running cloud integration docs by @WordsofDefiance in https://github.com/locustio/locust/pull/2275
Fix exception grouping for requests with both catch_response and name arguments by @ianmetcalf in https://github.com/locustio/locust/pull/2276
Improve documentation structure by @THUzxj in https://github.com/locustio/locust/pull/2278
Fix setuptools deprecation warnings by @heyman in https://github.com/locustio/locust/pull/2281
Stats in json to stdout (new command line option --json) by @AndersSpringborg in https://github.com/locustio/locust/pull/2269

New Contributors

@WordsofDefiance made their first contribution in https://github.com/locustio/locust/pull/2275
@ianmetcalf made their first contribution in https://github.com/locustio/locust/pull/2276
@THUzxj made their first contribution in https://github.com/locustio/locust/pull/2278
@AndersSpringborg made their first contribution in https://github.com/locustio/locust/pull/2269

Full Changelog: https://github.com/locustio/locust/compare/2.14.0...2.14.1

Open source →

Additional notes

Add --json to send stats to stdout as json by @AndersSpringborg in https://github.com/locustio/locust/pull/2269

Open source →

2.14.1.dev293 Jan 2023pre-release

Nothing published for this version

2.14.1.dev2023 Dec 2022pre-release

Nothing published for this version

2.14.1.dev1521 Dec 2022pre-release

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2.14.1.dev1016 Dec 2022pre-release

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2.14.1.dev713 Dec 2022pre-release

Nothing published for this version

2.14.013 Dec 20222 sources agree

Add rest method to FastHttpUser to facilitate easy REST/JSON API testing

Add rest method to FastHttpUser to facilitate easy REST/JSON API testing (https://docs.locust.io/en/stable/increase-performance.html#rest)

What's Changed

GRPC example - rewrite using interceptor by @zifter in https://github.com/locustio/locust/pull/2272
Add RestUser by @cyberw in https://github.com/locustio/locust/pull/2273
Move the rest method into FastHttpUser instead of RestUser. by @cyberw in https://github.com/locustio/locust/pull/2274

New Contributors

@zifter made their first contribution in https://github.com/locustio/locust/pull/2272

Full Changelog: https://github.com/locustio/locust/compare/2.13.2...2.14.0

Open source →

2.13.3.dev2213 Dec 2022pre-release

Nothing published for this version

2.13.3.dev912 Dec 2022pre-release

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2.13.3.dev511 Dec 2022pre-release

Nothing published for this version

2.13.29 Dec 20222 sources agree

Fix: Ask worker to reconnect if master gets a broken RPC message by @marcinh in https://github.com/locustio/locust/pull/2271

What's Changed

Fix: Ask worker to reconnect if master gets a broken RPC message by @marcinh in https://github.com/locustio/locust/pull/2271

Full Changelog: https://github.com/locustio/locust/compare/2.13.1...2.13.2

Open source →

2.13.2.dev158 Dec 2022pre-release

Nothing published for this version

2.13.11 Dec 2022

Convert browser recordings into locustfiles automatically using har2locust! (documentation)

What's Changed

Tiny performance enhancements by @cyberw in https://github.com/locustio/locust/pull/2240
Replace datetime.utcnow() with datetime.now(tz=timezone.utc), as it is kind of an antipattern by @cyberw in https://github.com/locustio/locust/pull/2244
Use C-style (percent) string formatting for all debug logging statements (improves performance) by @cyberw in https://github.com/locustio/locust/pull/2245
Update documentation for Environment.parsed_options by @klazuka in https://github.com/locustio/locust/pull/2247
Added a better working docker command for Windows users by @MagnusNordboe in https://github.com/locustio/locust/pull/2248
Small fixes to documentation by @jscanlannyc in https://github.com/locustio/locust/pull/2254
auto generated locustfiles from browser recordings using har2locust (documentation) by @cyberw in https://github.com/locustio/locust/pull/2259
Dont reset connection to worker if master receives a corrupted zmq message by @marcinh in https://github.com/locustio/locust/pull/2266

New Contributors

@klazuka made their first contribution in https://github.com/locustio/locust/pull/2247
@MagnusNordboe made their first contribution in https://github.com/locustio/locust/pull/2248
@jscanlannyc made their first contribution in https://github.com/locustio/locust/pull/2254

Full Changelog: https://github.com/locustio/locust/compare/2.13.0...2.13.1

Open source →

Additional notes

Document har2locust (auto generation of locustfiles from browser recordings) https://github.com/locustio/locust/pull/2259
Dont reset connection to worker if master receives a corrupted zmq message by @marcinh in https://github.com/locustio/locust/pull/2266
Other minor fixes

Open source →

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