A config file diff compares two configuration files and shows exactly which keys were added, removed, or changed in value. Supports .env, .ini, .properties, and .toml formats — ideal for catching environment mismatches before deployment.
How to Use the Config File Diff Tool
Managing multiple environments means keeping config files in sync. A single missing key in production or a mismatched value in staging can cause hard-to-debug failures. This config file diff tool makes it instant to see what changed between two versions of any config file format.
Step 1: Paste Your Config Files
Paste your original config file into the left panel and the modified version into the right. Both panels accept any of the common formats: .env files with KEY=VALUE pairs, .ini files with section headers, .properties files from Java applications, or basic .toml configurations.
Step 2: Choose a Format (or Use Auto-detect)
The Auto-detect option identifies the file format from the content automatically. If your file has [section] headers, it's treated as INI. Simple KEY=VALUE lines are treated as .env. You can override detection with the format dropdown when needed.
Step 3: Read the Color-coded Diff
Click Compare and the tool displays a table of every key with its status. Green rows are new keys added in the modified file. Red rows are keys deleted from the original. Yellow rows are keys present in both files where the value changed. Gray rows are unchanged keys shown for context.
Common Use Cases
Use the config file diff to compare development vs. production .env files before a deployment, review what changed in a colleague's configuration PR, verify that a feature branch didn't accidentally override critical keys, or audit what environment variables differ between Docker containers.
FAQ
Is this config file diff tool free?
Yes, completely free with no account or signup required. All parsing and comparison runs locally in your browser — your config files are never uploaded anywhere.
Which config file formats are supported?
The tool supports .env (KEY=VALUE), .ini (sections with key=value), .properties (key=value or key:value), and basic .toml (flat key=value). The Auto-detect mode identifies the format from the content structure automatically.
How does auto-detection work?
The tool checks for INI section headers ([section]), TOML-style values (key = value with quoted strings or arrays), and defaults to .env/.properties for simple KEY=VALUE content. You can always override with the format dropdown.
Can I compare files with comments?
Yes. Lines starting with # or ; are treated as comments and excluded from comparison. Only key-value pairs and section headers are compared, so you can safely paste config files with inline comments.
What does each color in the diff output mean?
Green rows indicate keys that were added in the right file. Red rows show keys removed compared to the left file. Yellow/orange rows mean the key exists in both files but the value has changed. Unchanged keys are shown in gray.
How do I compare .env files between environments?
Paste your development .env on the left and your production .env on the right. The tool will show any missing keys, extra keys, and value differences — perfect for catching environment mismatches before deployment.