---
id: tuna
version: "0.5.15"
license: GPL-3.0-or-later
license_treatment: copyleft
maintenance: active
---

# tuna — Visualize Python performance profiles

License: copyleft · Maintenance: active · Downloads: 252.7K/mo

## What it is and what it does

tuna is a lightweight Python profile viewer that reads output from Python's built-in cProfile and importtime profilers and displays them in an interactive web interface. It was designed as a modern alternative to SnakeViz, focusing on accuracy: it only displays timing information that can be reliably reconstructed from profile data, avoiding the incorrect call-tree reconstructions that SnakeViz produces. The tool uses d3 and bootstrap for visualization and has no runtime dependencies, making it quick to install and run.

You generate a profile by running your Python code with cProfile or importtime, then pass the resulting file to tuna's command-line interface. tuna launches a web viewer showing the call tree, function timings, and performance bottlenecks. It also includes IPython magic commands for profiling code directly in notebooks, offering a drop-in replacement for the prun magic.

Use it for:

- Identify which functions consume the most CPU time in a Python application.
- Analyze import-time performance to find slow module initialization.
- Debug performance regressions by comparing profiles across code versions.
- Visualize call hierarchies to understand which code paths dominate execution time.
- Profile IPython/Jupyter notebooks using the tuna magic command.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

tuna visualizes Python performance profiles in an interactive web interface, showing runtime and import-time profiling data with minimal dependencies.

Yes. tuna is actively maintained, has no runtime dependencies, supports current Python versions (3.10+), and solves a real problem—accurate profile visualization—that SnakeViz handles incorrectly. The GPLv3 license is a constraint for proprietary use but not a blocker for most development workflows. Install it if you need to understand where your Python code spends time.

## Install

pip install tuna
uv add tuna
poetry add tuna

## Installing tuna

Before you install: Low friction: pure Python wheel with no runtime dependencies. Actively maintained as of June 2026, with 1597 repository stars and regular releases since 2018.

License in practice: GPLv3 copyleft license. Any derivative work or distribution must also be licensed under GPLv3; using tuna in proprietary projects requires careful consideration of linking and distribution obligations.

Quickstart:

pip install tuna

python -mcProfile -o program.prof yourfile.py
tuna program.prof

Requires Python 3.10 or later.

Verify before relying:

- Whether the web interface requires a specific browser or JavaScript runtime to function.
- Whether tuna can be used programmatically as a library or only as a CLI tool.
- Performance characteristics when analyzing very large profile files.

## Package facts

- License: GPL-3.0-or-later (copyleft)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 252.7K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

python profile visualization, performance profiling viewer, cprofile viewer, python runtime analysis, import time profiler, call tree visualization, performance bottleneck analysis, profiling, performance-analysis, visualization

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