Compress YAML Files Online — Browser-Only YAML Compressor

This YAML compressor shrinks .yaml and .yml files by removing comments and blank lines, tightening indentation, or turning the whole file into a single line, without changing the data inside. Paste a file or open one and the result updates as you type. Every result is read back and compared with your original under both YAML 1.2 and YAML 1.1 rules, so you know it means exactly the same thing before you download it. It also works as a quick YAML validator: if the file has a mistake, you’ll see the line and column.

How to compress a YAML file

1. Paste your YAML into the left box, use Open file, or drag the file onto the box.
2. Pick a Style. Keep layout only removes comments and blank lines. Compact also shrinks indentation. One line gives the smallest file.
3. Check the Changes tab to see which lines were removed or edited, and the Check tab to confirm the data is unchanged.
4. Copy the result, download the smaller .yaml, or download a .gz copy.

The three styles

Before and after

# Web service
services:
  web:
    image: nginx:1.27   # pinned version
    ports:
      - "8080:80"
    environment:
      DEBUG: "no"

Keep layout gives:

services:
  web:
    image: nginx:1.27
    ports:
      - "8080:80"
    environment:
      DEBUG: "no"

One line gives:

{services: {web: {image: "nginx:1.27", ports: ["8080:80"], environment: {DEBUG: "no"}}}}

Why your data stays the same

YAML is easy to break by accident, because the same text can mean different things to different parsers. In YAML 1.1, used by PyYAML, Ruby and older Go libraries, an unquoted no is the boolean false and 0777 is the number 511. In YAML 1.2, used by most newer parsers, they’re the text “no” and the number 777. A compressor that rewrites "no" as no, or 0777 as 777, quietly changes your data for some of the programs that read it.

This tool keeps the exact spelling of every number, word and quoted value. It then reads both your original and the result with YAML 1.2 rules and again with YAML 1.1 rules, and compares every key and value. If anything differs, download is turned off and you’ll see why. It was tested on more than 3,400 real YAML files and the full official YAML test suite.

What’s never changed

• Keys, values and the order they appear in
• Quoted strings, including their quote style
• Multi-line text in | and > blocks, including the line breaks and spacing inside them
• Anchors, aliases and merge keys (&base, *base, <<)
• Tags like !!str or !Ref, and the --- between multiple documents
• Line endings. Files with Windows CRLF line endings keep them.

Should you use the GZIP download?

GZIP usually makes a YAML file 50–65% smaller, and even smaller after minifying. That’s great for backups, storage and sending files over slow connections. But tools like kubectl, Docker Compose and GitHub Actions can’t read a .gz file directly. Unzip it first (gunzip config.yaml.gz on Linux and macOS, or 7-Zip on Windows). If you need a smaller file an app can load, use the regular .yaml download.

Frequently asked questions