Pympler
A development tool to measure, monitor and analyze the memory behavior of Python objects.
Decision gist · record as of 2026-08-14
Yes, if you need to diagnose memory behavior in Python applications. Pympler is well-established, permissively licensed, has low install friction, and carries no known vulnerabilities. The aging maintenance status (777 days since release) is a minor concern but not a blocker—recent commits show active stewardship. Install it when memory profiling is part of your development workflow.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- On Windows, pywin32 must be installed as a dependency; on Linux and macOS, no external dependencies beyond Python standard library.
- Low install friction with a pure-Python implementation on Linux and macOS; Windows requires pywin32.
- The package is aging (777 days since last release) but remains actively maintained with recent commits and a stable repository.
License · maintenance · safety
Apache License, Version 2.0 (permissive) — Apache License 2.0 is permissive, allowing commercial and private use with minimal restrictions—suitable for most development and production scenarios.
last release 2024-06-28 (777 days) · last repo commit 2025-06-07 · 1,408 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 6,244,156 downloads/mo, #1,948 on PyPI
Alternatives
Verify before relying
pip install Pympler
from pympler import asizeof
print(asizeof.asizeof([1, 2, 3]))- Whether the aging maintenance status (777 days since release) affects compatibility with Python versions beyond 3.12.
- Real-world performance impact when profiling large, long-running applications with many objects.
What it is and what it does
Pympler is a memory profiling and analysis tool for Python applications. It combines three integrated subsystems—asizeof for object size measurement, muppy for online application monitoring, and a class tracker for offline lifetime analysis—along with a web frontend for visualizing process statistics and garbage collection behavior. The tool is written entirely in Python and requires no external dependencies on Linux and macOS; Windows users need pywin32.
Developers use Pympler to diagnose memory issues in running applications: identifying which objects consume the most memory, tracking how object lifetimes correlate with memory growth, and spotting unexpected memory bloat. It's particularly useful during development and debugging phases when memory behavior is unclear or suspected to be problematic.
Use it for
- Identify which Python objects are consuming the most memory in a long-running application.
- Track the lifetime and growth patterns of specific classes to detect memory leaks or unexpected retention.
- Monitor memory behavior of a running application in real time using muppy's online profiling.
- Analyze garbage collection and heap statistics through the web profiling frontend.
- Diagnose memory bloat during development before deploying to production.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you need to diagnose memory behavior in Python applications.
Pympler is well-established, permissively licensed, has low install friction, and carries no known vulnerabilities. The aging maintenance status (777 days since release) is a minor concern but not a blocker—recent commits show active stewardship. Install it when memory profiling is part of your development workflow.
Install
pympler on PyPI
Before you install
Low install friction with a pure-Python implementation on Linux and macOS; Windows requires pywin32. The package is aging (777 days since last release) but remains actively maintained with recent commits and a stable repository.
On Windows, pywin32 must be installed as a dependency; on Linux and macOS, no external dependencies beyond Python standard library.
License in practice
Apache License 2.0 is permissive, allowing commercial and private use with minimal restrictions—suitable for most development and production scenarios.
Quickstart
pip install Pympler
from pympler import asizeof
print(asizeof.asizeof([1, 2, 3]))Verify before relying
- Whether the aging maintenance status (777 days since release) affects compatibility with Python versions beyond 3.12.
- Real-world performance impact when profiling large, long-running applications with many objects.
Package facts
| License | Apache License, Version 2.0 permissive |
| Python support | Supports the current Python release >=3.6 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 1 packagepywin32 |
| Maintenance | Aging 777 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 6,244,156 / month, #1,948 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 4 - BetaEnvironment :: ConsoleIntended Audience :: DevelopersLicense :: OSI Approved :: Apache Software LicenseOperating System :: OS IndependentProgramming Language :: PythonProgramming Language :: Python :: 3Programming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.6Programming Language :: Python :: 3.7Programming Language :: Python :: 3.8Programming Language :: Python :: 3.9Topic :: Software Development :: Bug Tracking |
Evidence: Pympler-1.1-py3-none-any.whl
Tags
Let your AI agent find packages like this
Example. Real query, live index.
You found this page by searching. An agent finds it by wishing: SkillFed indexes 14,416 PyPI packages by what they can do, searchable in plain language.
wish › “object size analysis”
- PymplerPympler measures, monitors, and analyzes memory behavior of Python…
- zope.sizeProvides a standard interface and adapter for retrieving object…
- objsizeMeasures the complete memory footprint of Python objects including…
Give your agent the search over MCP, or paste the wish link into any chat.
More Software Development packages
Provides backported and experimental type hints for Python 3.9+, allowing use of newer typing features on older Python versions and enabling early experimentation with type system PEPs before they enter the standard library.
NumPy provides an N-dimensional array object and a comprehensive suite of mathematical, linear algebra, Fourier transform, and random number functions for scientific computing in Python.
FastAPI is a Python web framework for building REST APIs using type hints, with automatic request validation, serialization, and interactive API documentation.
Provides a way to document function parameters, class attributes, return types, and variables inline using Python's `Annotated` type hint syntax instead of traditional docstrings.
Typer builds command-line applications from Python functions using type hints, automatically generating help text, argument parsing, and shell completion.
Install it if you are building CLIs in Python.
Distlib provides low-level packaging utilities for building, distributing, and managing Python software—including metadata handling, version specifiers, wheel support, script installation, and dependency resolution.
See also objsize · memray · mozleak · py-spy · scalene · fastapi-profiler · binsize · intel-pti · pyroscope-io · guppy3