Formatted requirements.txt will appear here...
Format options
What is Python Requirements.txt Generator & Validator?
A requirements.txt file declares the Python packages your project depends on, along with optional version constraints. When packages are listed without version pins, pip installs whatever is latest at the time — and a new release days later can break your application in production. This tool parses your requirements.txt, validates every line against PyPI naming rules (PEP 508), flags missing version pins and duplicate entries, and exports a clean, sorted file you can commit with confidence.
How to Use
- Paste your requirements.txt content into the input panel on the left.
- Click "Validate & Format" to parse the file and check for issues.
- Review errors (invalid syntax, duplicate packages) and warnings (unpinned versions).
- Toggle formatting options: sort alphabetically, keep or strip comments, keep environment markers.
- Click "Copy Output" to copy the cleaned and formatted requirements.txt.
- Use "Load Sample" to see a file with common issues pre-loaded for demonstration.
Why Use This Tool?
Tips & Best Practices
- Use == for exact pinning in production (requests==2.31.0) to guarantee reproducible installs across environments
- Use ~= for compatible releases: flask~=2.3 means >=2.3, <3.0 — a good balance for library dependencies
- Generate a pinned file from your active environment with pip freeze > requirements.txt
- Split requirements into separate files: requirements.txt for production, requirements-dev.txt for testing and linting
- Use pip-tools (pip-compile) to automatically resolve and pin all transitive dependencies from a clean specification
Frequently Asked Questions
What is the difference between == and ~= in requirements.txt?
The == operator pins an exact version: requests==2.31.0 installs only 2.31.0. The ~= operator specifies a compatible release: flask~=2.3 means ">=2.3, <3.0", allowing patch and minor updates but blocking major version bumps. Use == for reproducible production deployments and ~= for libraries where you want to allow safe upgrades.
Why are unpinned packages dangerous in production?
Writing just "requests" without a version constraint tells pip to install the latest version at install time. Different developers, CI runners, or deployment environments may resolve different versions. A new release might introduce breaking changes or security regressions. Always pin versions in production: requests==2.31.0.
How do I generate requirements.txt from my current environment?
Run "pip freeze > requirements.txt" in your activated virtual environment. This outputs every installed package with its exact version. For a cleaner file listing only your direct dependencies (not transitive ones), use pipreqs: install it with pip install pipreqs, then run pipreqs /path/to/your/project.
When should I NOT use this validator?
This tool is designed for pip requirements.txt files and does not handle Poetry (pyproject.toml), Conda (environment.yml), or Pipenv (Pipfile) formats. It also does not resolve dependency conflicts or check whether pinned versions are available on PyPI — use pip check or pip-tools for that.
Is my requirements.txt data kept private?
Yes. All parsing, validation, and formatting runs entirely as client-side JavaScript in your browser. Your requirements.txt content is never sent to any server, API, or third-party service. You can safely validate proprietary dependency lists without any data leaving your machine.
What does the === (arbitrary equality) operator mean?
The === operator is the arbitrary equality operator defined in PEP 440. It matches an exact version string including local version labels, such as 1.0.0+local.1. It is rarely needed and is non-portable across package managers. The validator flags it as informational and recommends using == instead unless you have a specific reason to use ===.
Real-world Examples
Cleaning Up a Legacy Requirements File
A project has a requirements.txt with 30 packages, some unpinned, some duplicated, and no consistent ordering. Paste it in, validate, sort alphabetically, and export a clean file ready for the next deployment.
flask==2.3.2 requests flask-cors>=3.0.0 requests>=2.28.0 sqlalchemy~=2.0
flask==2.3.2 flask-cors>=3.0.0 requests>=2.28.0 sqlalchemy~=2.0 Warnings: "requests" was duplicated (merged). Original "requests" had no version pin.
Catching an Unpinned Dependency Before Deployment
A developer adds "redis" without a version to requirements.txt. The validator flags it as a warning, and the team pins it to redis==5.0.1 before merging.
flask==2.3.2 redis psycopg2-binary==2.9.7
Warning: "redis" has no version pin — unpinned packages can cause deployment inconsistencies