Observability & Monitoring

py-spy

A sampling profiler for Python programs written in Rust.

Status
Generally available
Last checked
Aging · Sep 2, 2026
License
Open source
Pricing
Free tier · from $0
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What it is

Py-Spy is a low-overhead sampling profiler that helps developers understand the performance characteristics of their Python applications. It provides insights into where time is being spent, making it easier to optimize and debug code.

Py-Spy stands out for its low-overhead and ability to attach to running processes without restarting them, making it ideal for production environments where minimal disruption is critical.

When it fits — and when it doesn’t

A good fit for

  • Developers who need to optimize the performance of their Python applications without significant overhead.

  • Teams working in production environments where profiling must be non-intrusive.

  • Individuals or teams looking for a tool that can attach to running processes and provide real-time insights.

Look elsewhere if

  • Projects requiring detailed line-by-line analysis as py-spy is a sampling profiler.

  • Applications written in languages other than Python, as it only supports profiling Python programs.

Known weaknesses

Each one links to the public issue, changelog or docs page it came from, where we have one.

  1. 01

    Limited support for multi-threaded applications

    Py-Spy may not accurately profile Python programs that heavily utilize threading or multiprocessing, leading to incomplete performance data.

  2. 02

    Complex setup and configuration for non-standard environments

    Setting up Py-Spy in complex containerized or virtualized environments can be challenging due to limited documentation on advanced configurations.

  3. 03

    Performance overhead when profiling I/O-bound applications

    Py-Spy's sampling profiler may introduce some performance overhead when used with IO-bound Python applications, which could skew the results slightly.

What it does well

  • Low-overhead sampling profiler for Python programs.

  • Visualizes CPU usage and flame graphs.

  • Can attach to running processes without restarting them.

Pricing

Free tier
YesOpen source — free to use
Paid from
$0
Model
Flat rate
Enterprise plan
No

Pricing not independently confirmed — check the vendor’s page.

Performance benchmarks

How Fast Is It?

Set up py-spy

Setup steps, common gotchas and what to check after 30 days.

Open the setup guide →