.env File Checker
Validate syntax, catch security risks, find duplicates, and format your environment files — free, no signup.
What is a .env File?
A .env file stores environment variables as KEY=value pairs. It's the standard way to configure applications across Node.js, Python, Docker, React, and Next.js projects. These files typically contain database credentials, API keys, and service URLs that shouldn't be hardcoded in your source code.
What Does This Tool Check?
Our .env checker validates your file for syntax errors (missing equals signs, invalid key names), duplicate keys, unquoted values with special characters, and potential security risks like exposed passwords, API keys, and tokens.
Why Should I Never Commit .env to Git?
Your .env file contains sensitive credentials that could give attackers access to your databases, APIs, and services. Always add .env to your .gitignore file and use a .env.example file with placeholder values for your team.
Frequently Asked Questions
What characters are allowed in .env keys?
Keys must start with a letter or underscore, followed by letters, digits, or underscores. Examples: DB_HOST, _PRIVATE_KEY, API_KEY_2. Spaces, dashes, and dots are not allowed.
Do I need to quote .env values?
Simple values like PORT=3000 don't need quotes. But values with spaces, semicolons, hashes, or other special characters should be quoted: MESSAGE="hello world". Use double quotes for variables that need interpolation, single quotes for literal strings.
What is a .env.example file?
A .env.example is a template committed to your repository that shows all required variables with placeholder or empty values. Team members copy it to .env and fill in their own values. This way everyone knows what config is needed without sharing secrets.
Can .env files have comments?
Yes, lines starting with # are treated as comments and ignored. Comments are a great way to document what each variable is for.
Does this tool store my data?
No. All validation runs entirely in your browser. Your .env content never leaves your machine or gets sent to any server.