User-Agent Generator Benchmark¶

Apple-to-apple performance comparison between zerodep useragent and ua-generator.

Test Environment

CPU: x86_64 Linux
Python: 3.10
Tool: pytest-benchmark 5.2.3 (mean values reported)
Reference: ua-generator 2.0+
Last Updated: 2026-04-29

Implementations¶

Implementation	File/Package	Description
zerodep	`useragent.py`	Single-file Chrome/Edge UA generator, stdlib only
ua-generator	(reference)	Multi-browser UA generator package

What Is Benchmarked¶

Both libraries generate User-Agent strings with matching Client Hints headers. The benchmark measures pure generation throughput -- no network I/O involved.

Test Scenarios¶

Scenario	Description
Default	Random browser + platform (no filters)
Chrome Desktop	`browser="chrome", device="desktop"`
Edge Mobile	`browser="edge", device="mobile"`
Headers	Generate UA + build full Client Hints headers via `.headers.get()`

Generation Performance (Mean)¶

Scenario	zerodep	ua-generator	Speedup
Default	3.1 μs	8.6 μs	2.7x faster
Chrome Desktop	3.9 μs	7.9 μs	2.0x faster
Edge Mobile	3.4 μs	9.2 μs	2.7x faster
Headers	5.2 μs	11.6 μs	2.2x faster

Key Takeaways¶

zerodep is 2-3x faster across all scenarios -- the simpler architecture (no dynamic plugin loading, no multi-browser dispatch) translates directly into throughput gains.
Both are extremely fast -- at 3-12 μs per generation, UA generation is never a bottleneck in any real application (a single HTTP request takes milliseconds).
Headers generation adds ~2 μs -- building the full Sec-CH-UA-* header set is lightweight for both libraries.
zerodep covers Chrome + Edge only -- this intentional scope reduction (vs ua-generator's Chrome/Edge/Firefox/Safari) is the main source of the speed advantage.
Zero pip dependencies -- zerodep uses only random from the standard library.

Run It Yourself¶

pip install pytest pytest-benchmark ua-generator
pytest useragent/test_useragent_benchmark.py --benchmark-only -v

Latest CI Results¶

Updated automatically on each release via Benchmark CI.