Env Linter

The .env text stays in your browser. Secret-looking values are masked. Analytics and ads may load on the page.

.env

Duplicate keys and unquoted values with spaces are flagged.

.env.example (optional)

Missing or extra keys are reported.

How to lint a .env file

Paste .env

Paste the file you want to check. The sample has a duplicate key and an unquoted value with spaces.
Optional example

Paste .env.example to see missing or extra keys.
Lint

Read duplicate keys, unquoted spaces, and export prefixes. Secrets appear masked.
Fix in your editor

Quote values that contain spaces and remove duplicate keys.

Common Use Cases

Duplicate Key Checks

Find repeated variable names that can make runtime configuration depend on parser order.

Example File Drift

Compare .env with .env.example and find missing or extra keys before release.

Dotenv Syntax Review

Find invalid names, missing equals signs, export prefixes, and unquoted values with spaces.

Secret Candidate Review

Find common token patterns and secret-like variable names, with candidate values masked in the report.

Why lint a .env file

Small mistakes in dotenv files fail at runtime. This page checks duplicate keys, unquoted values with spaces, export prefixes, and key drift. Secret-looking values are masked in the findings. The text is not uploaded to FindUtils. Analytics or ads on the page may still load.

FindUtils Env Linter checks common KEY=value files for mistakes that can change application configuration. It reports duplicate keys, invalid lines, invalid names, export prefixes, and unquoted values that contain spaces.

An optional .env.example comparison finds keys that exist in only one file. The report also marks common token patterns and secret-like key names, and it masks those candidate values in the table. Detection is heuristic and cannot identify every secret.

Linting runs in your browser and does not change the pasted files. Use the JSON Formatter for JSON configuration, and use the JWT Decoder only with non-sensitive test tokens.

How it compares

A basic dotenv parser can tell you whether it accepts a file. FindUtils Env Linter also reports duplicate keys and example-file drift, but it does not replace application startup checks, framework-specific parsing, or a dedicated secret scanner.

Use the HMAC Generator for controlled signature test data. Do not paste a production secret into any unrelated tool.

Env Linting Tips

Paste .env.example with .env when you need a key drift report.
Remove duplicate keys even when your current dotenv parser accepts them.
Quote a value that contains spaces so its intended boundary is clear.
Treat secret masking as a warning aid, not a complete secret scanner.
Fix the source file in your editor because this tool does not change pasted text.

Frequently Asked Questions

Does this upload secrets?

No. FindUtils runs the lint in your browser and does not upload or store the .env text. Secret-looking values are masked in the result table, but detection is not complete.

What does it flag?

It flags duplicate keys, invalid lines, invalid names, export prefixes, unquoted spaces, and selected secret candidates. It can also compare keys with an optional .env.example file.

Is this a parser for every dotenv dialect?

No. FindUtils Env Linter checks common dotenv file shapes. It is not a complete shell parser or a framework-specific configuration loader.

Can I compare two files?

Yes. Paste .env and the optional .env.example text. The report identifies keys that exist in only one input. To also see which shared keys have different values, compare the two files in Env Diff, and to combine two files into one, use Env Merge.

Does it change my file?

No. The tool reports issues and displays parsed keys only. Make each correction in your source file and run the lint again.

Does masking find every secret?

No. It recognizes selected token patterns and secret-like key names. An unrecognized sensitive value can remain visible, so review the input and result carefully.

What does the .env.example comparison report?

It reports keys that are missing from .env. It also reports keys present in .env but absent from .env.example.

Are comments and blank lines errors?

No. The linter ignores blank lines and comment lines. Other non-empty lines must use a supported KEY=value shape.

Does it validate database URLs or API credentials?

No. It checks file shape and selected secret patterns. It does not contact a database or API, and it cannot prove that a credential works.

Does it support shell scripts?

No. It checks common dotenv files only. Shell expansion, commands, substitutions, and full shell grammar are outside its scope.

Run it from code

$ curl -X POST \
  api.findutils.com/api/tools/env-linter/execute \
  -d '{"env":"FOO=1\nFOO=2\n","example":"FOO=\nBAR=\n"}'

$ claude mcp add findutils \
  --transport http https://mcp.findutils.com/
# then call findutils:env_linter

API reference Add to Claude