Free Online .env Formatter & Validator
Parse, validate, and format .env environment files online. Detects duplicate keys, invalid syntax, and formatting issues — 100% client-side, no upload required.
100% Client-Side · Your data never leaves your browserHow to Use .env Formatter & Validator
Paste your .env file content into the Input area, then use the toolbar to format or validate it:
- Format — parses your file and outputs a clean, normalized version. Use the Sort A–Z toggle to sort keys alphabetically, and Align = to pad keys so all equals signs line up in a column.
- Validate — checks for syntax errors (missing
=, keys with spaces) and duplicate keys without modifying the content. Issues are shown in the table below. - Sample — loads a representative example to explore the tool's behavior.
Press Ctrl/Cmd+Enter to format, or Ctrl/Cmd+K to clear. Duplicate keys are highlighted in amber; hard errors appear in red. Use the Copy button to copy the formatted output.
Frequently Asked Questions
What is a .env file?
A .env file (dotenv file) is a plain-text configuration file used to store environment variables for an application. Each line follows the KEY=VALUE format. Libraries like dotenv (Node.js), python-decouple (Python), and godotenv (Go) automatically load these variables into the process environment at startup, keeping secrets and configuration out of source code.
What quoting rules apply to .env values?
Values can be unquoted, double-quoted, or single-quoted. Double quotes allow escape sequences and are commonly used for values containing spaces or special characters (e.g., DB_PASSWORD="my secret"). Single quotes treat the value as a literal string with no escape processing. Unquoted values are read as-is up to any inline comment.
How do comments work in .env files?
Lines beginning with # are treated as full-line comments and are ignored by parsers. Inline comments (e.g., PORT=3000 # default port) are supported by some parsers but not all. For maximum compatibility, prefer separate comment lines rather than inline comments for important values.
What does the "export" prefix do?
Some .env files prepend export to variable names (e.g., export DATABASE_URL=...) so the file can also be sourced directly in a Bash shell with source .env. Most dotenv libraries strip the export keyword when loading the file. This tool parses and handles the export prefix correctly.
Does .env support multiline values?
Multiline values are supported via a trailing backslash at the end of a line (line continuation), or by wrapping the entire value in double quotes and including literal newlines. Support varies across dotenv libraries, so always test with your specific runtime.
Is my .env file safe to paste here? Are values sent to a server?
Yes — all parsing, validation, and formatting runs entirely in your browser using JavaScript. Nothing is sent to any server. However, as a best practice, consider replacing sensitive production secrets with placeholder values before pasting into any online tool.