uv vs pip-tools: Which Python Locking Tool for CI?
pip-tools popularized compiling pinned requirements; uv does the same job far faster and adds a project workflow.
pip-tools provides pip-compile and pip-sync to turn loose requirements into a fully pinned requirements.txt. uv (from Astral) is a Rust-based tool that resolves, locks, and installs dependencies at high speed and can replace pip-compile via uv pip compile.
| pip-tools | uv | |
|---|---|---|
| Implementation | Python | Rust |
| Resolve/compile speed | Moderate | Much faster |
| Lock output | requirements.txt (pinned) | requirements.txt or uv.lock |
| Installs deps | Via pip / pip-sync | Built in (uv pip / uv sync) |
| Python version management | No | Yes, can install Pythons |
In CI
uv compiles and installs dependencies much faster than the pip-compile + pip-sync flow, which shortens the slowest part of many Python pipelines. uv pip compile is designed as a drop-in for pip-compile, so the requirements.txt workflow carries over. pip-tools remains a fine, minimal choice when you only need to pin a requirements file and do not want a new binary in your image.
Migration effort
Swapping pip-compile for uv pip compile is usually low-friction and keeps your existing requirements.in / requirements.txt layout. Verify resolution on complex constraint sets, since resolver behavior can differ. Cache the resolved requirements keyed on your input files either way.
The verdict
Want the fastest compile/install and optional Python management: uv. Want a tiny, well-understood pin-the-requirements tool with no new runtime: pip-tools. uv pip compile is a near drop-in if speed is your bottleneck.