YAML Formatter
Format and validate YAML online, free and private.
Paste or upload your YAML, choose 2 spaces, 4 spaces or Tab, and click Beautify YAML to get clean, consistently indented output. Validate checks your syntax and shows the exact line and column of any error. Sort keys A–Z, pick a quote style and format multi-document files. Your YAML never leaves your browser. Free, with no sign-up.
No Sign-Up, Nothing to Install
Beautify and Check YAML Syntax
YAML Never Leaves Your Browser
Line and Column Shown
YAML output is rebuilt from the data, so comments aren’t kept. YAML also forbids tabs, so 2 spaces are used when you pick Tab.
Tip: press Ctrl + Enter inside the input box to beautify. You can also drop a file onto the input.
Private by design: your code is formatted in your browser and never uploaded. Protected by Cloudflare Turnstile.
How Do You Format YAML Online?
To format YAML online, paste your YAML into the YAML input box, upload a .yaml or .yml file, or click Sample. Choose 2 spaces, 4 spaces or Tab, then click Beautify YAML. The formatted YAML appears in the Result box, ready to Copy or Download. To only check your syntax, click Validate.
YAML uses indentation to show structure, so one stray space or tab can break a Kubernetes manifest, a Docker Compose file or a GitHub Actions workflow. Hand-edited and copied YAML often ends up with mixed indentation and quotes. A YAML formatter rewrites the file with consistent spacing, so it is easier to read, review and commit.
Everything happens on your own device. js-yaml, a widely used open-source YAML parser, reads your YAML in the browser and writes it back out with the settings you choose. Your YAML is not sent to Teasoft or anyone else, so you can safely format config files that contain hostnames, internal settings and other private values.
What happens to your YAML when you format it:
| Part of your YAML | In the formatted YAML | Good to know |
|---|---|---|
| Keys, values and lists | Unchanged | Every key, value, list and nested map stays the same. Only spacing and layout change. |
| Indentation | Rebuilt | Set to 2 or 4 spaces. YAML does not allow tabs, so the Tab option uses 2 spaces. |
| Comments | Removed | The output is rebuilt from the parsed data, so # comments are not kept. |
| Quotes | Normalised | Strings are quoted only when needed, using single or double quotes as you prefer. |
| Anchors and aliases | Expanded | &anchor, *alias and << merge keys are written out in full where they are used. |
| Multiple documents | Kept | Documents separated by — stay separate and in the same order. |
Common reasons to format YAML
- Cleaning up Kubernetes manifests, Helm values and Kustomize files before you apply them.
- Fixing indentation in Docker Compose files after copying services between projects.
- Tidying GitHub Actions, GitLab CI, Azure Pipelines and other CI/CD workflow files.
- Checking Ansible playbooks, OpenAPI specs and app config files for syntax errors.
- Reducing noisy diffs by using one indentation and quote style across your team.
- Making YAML generated by scripts and tools easy for people to read and review.
What each control does:
| Control | What it does | When to use it |
|---|---|---|
| YAML input box | Holds the YAML you want to format | Paste or type YAML, or drop a file onto it. Files up to 10 MB. |
| Upload, Paste, Sample and Clear | Opens a file, pastes from the clipboard, loads an example or empties the box | Use Sample to try the tool and Clear to start over. |
| Indentation | Sets 2 spaces, 4 spaces or Tab | 2 spaces is the most common style for Kubernetes and CI files. |
| End with a new line | Adds a line break at the end of the output | Keep it on. Many linters and Git tools expect a final new line. |
| Sort keys A–Z | Puts map keys in alphabetical order | Compare two files or reduce noisy diffs. |
| Don’t indent list items | Writes list dashes level with their parent key | Match teams and linters that keep the dash flush with the key. |
| Quote style | Prefers single or double quotes | Pick the style your project or linter uses. |
| Beautify YAML and Validate | Formats the YAML, or only checks the syntax | Errors show the line and column to fix. |
| Copy, Download and Use as input | Copies, saves or moves the result back into the input | Use as input lets you format again with new settings. |
Good to know
- Comments are not kept. The output is rebuilt from the parsed data, so lines starting with # are removed. Keep your original file if you need them.
- Tabs are not allowed in YAML. The YAML specification forbids tabs for indentation, so the Tab option uses 2 spaces instead.
- Anchors are expanded. Values that use &anchor, *alias or << merge keys are written out in full, so the file may get longer.
- Sorting changes order, not data. Sort keys A–Z keeps every value the same, but review the diff before you commit a sorted file.
- Quick shortcut. Press Ctrl + Enter inside the input box to beautify, or drop a .yaml or .yml file onto it to open it.
What You Can Do With This Tool
- Format YAML for free. No software to install and no account needed.
- Beautify messy YAML. Turn uneven, hard-to-read YAML into clean, consistent output.
- Validate YAML syntax. Check whether a file parses without changing your input.
- Find errors fast. Error messages show the exact line and column to fix.
- Choose your indentation. Use 2 spaces or 4 spaces to match your project style.
- Sort keys A–Z. Put map keys in alphabetical order for easier comparison.
- Control list indentation. Indent list items under their key or keep them flush.
- Pick a quote style. Prefer single or double quotes for strings that need them.
- Format multiple documents. Files with several documents separated by --- are formatted in one go.
- Open files directly. Upload or drop .yaml and .yml files up to 10 MB.
- Copy or download. Copy the result, save it as a file or send it back to the input.
- Keep your data private. Formatting runs in your browser and nothing is uploaded.
Which Formatter Should I Use?
Use the YAML Formatter for YAML and YML files. For other code and data formats, try these free Teasoft formatters.
How to Format YAML (3 Steps)
Add your YAML
Paste YAML into the YAML input box, click Upload to open a .yaml or .yml file, or drop a file onto the box. Files up to 10 MB are supported. Not sure where to start? Click Sample to load an example.
Choose your settings
Pick 2 spaces, 4 spaces or Tab. Turn on End with a new line, Sort keys A–Z or Don’t indent list items if you need them, and choose single or double quotes.
Beautify and download
Click Beautify YAML or press Ctrl + Enter. Copy the result, Download it or click Use as input to format again. If there is an error, fix the line and column shown and try again.
Tip: to only check whether a file is valid, click Validate instead of Beautify YAML. It checks the syntax without changing your input. Because JSON is valid YAML, you can also paste JSON and click Beautify YAML to turn it into clean, block-style YAML. To format plain JSON, use the JSON Formatter.
Which Setting Should I Use?
| Task | Use | Why |
|---|---|---|
| Kubernetes, Helm or Docker Compose files | 2 spaces | Matches the style used in most official examples and charts. |
| GitHub Actions or GitLab CI workflows | 2 spaces, End with a new line | The common convention in workflow docs, templates and linters. |
| Comparing two versions of a config | Sort keys A–Z | Keys line up in the same order, so real differences are easy to spot. |
| Checking a file before you deploy | Validate | Confirms the syntax and shows any error without changing your input. |
| Lists written flush with their key | Don’t indent list items | Keeps the output in line with your existing files. |
| Files with comments you need | Validate, or keep a copy | Beautify YAML removes comments, so don’t overwrite your original. |
Getting better results when you format YAML
- Use spaces, never tabs. Set your code editor to insert spaces in .yaml and .yml files to avoid parse errors.
- Quote values that should stay text. Version numbers like 1.10, codes like 0123 and words like true can be read as numbers or booleans.
- Keep a copy with comments. Formatting removes # comments, so save your original before you replace it.
- Fix the first error first. One wrong indent can cause errors further down. Fix the reported line, then validate again.
- Agree on one style. Use the same indentation and quote style across your team so every file and diff looks alike.
After you format your YAML
- Check the result. Compare it with your original and make sure no comments you need were lost.
- Run your platform checks. Valid YAML can still be an invalid Kubernetes or CI config, so run your tool’s own checks before you deploy.
- Commit it separately. Commit formatting changes apart from real edits so reviews stay easy.
- Format related files. Tidy other configs with the JSON Formatter and XML Formatter.
Frequently Asked Questions
How do I format YAML online?
Paste your YAML or upload a .yaml or .yml file, choose 2 spaces, 4 spaces or Tab, and click Beautify YAML. Then copy or download the clean result.
Is the YAML Formatter free?
Yes. It is completely free, with no sign-up, no account and nothing to install.
Is my YAML uploaded to a server?
No. Your YAML is parsed and formatted inside your browser, so it never reaches Teasoft or any other server.
How do I validate YAML?
Paste your YAML and click Validate. If it is valid, the tool confirms it. If not, it shows the error with the exact line and column.
Why does my YAML show an error?
Most errors come from wrong indentation, tabs, a missing space after a colon, or an unclosed quote or bracket. Fix the line shown and validate again.
Can I use tabs in YAML?
No. The YAML specification does not allow tabs for indentation. If you choose Tab, the formatter uses 2 spaces so your output stays valid.
Does the formatter keep my comments?
No. The output is rebuilt from the parsed data, so # comments are removed. Keep your original file if you need them.
What indentation should I use for YAML?
2 spaces is the most common choice and is used in most Kubernetes, Docker Compose and GitHub Actions examples. 4 spaces is also valid.
What does Sort keys A–Z do?
It puts the keys in every map in alphabetical order. Your data stays the same, but files become easier to compare.
What does Don’t indent list items do?
It writes list dashes at the same level as their parent key instead of indenting them. Both styles are valid YAML.
Can it format files with multiple YAML documents?
Yes. Documents separated by --- are each formatted and kept in order, so Kubernetes files with several resources work fine.
What happens to anchors and aliases?
They are expanded. Values referenced with *alias or merged with << are written out in full, so the output has no anchors.
Can I format Kubernetes, Docker Compose or GitHub Actions files?
Yes. They are standard YAML. The tool checks YAML syntax, not platform rules, so also run your platform’s own checks before you deploy.
Can I convert JSON to YAML here?
Yes. JSON is valid YAML, so paste JSON and click Beautify YAML to get block-style YAML. Use the JSON Formatter to format plain JSON.
What is the maximum file size?
You can open files up to 10 MB or paste up to 5 million characters. Very large files may take a few seconds on slower devices.
Does it work on my phone?
Yes. It works in Chrome and Safari on Android and iPhone, and on tablets. You can paste YAML or open a file from your device.
Do I need to install anything?
No. Everything runs in your web browser. There is no app, extension or account needed.
Which browsers are supported?
It works in Chrome, Edge, Firefox, Safari and other modern browsers on Windows, Mac, Linux, Android and iOS.
About Teasoft's YAML Formatter
Teasoft's YAML Formatter is a free online tool that beautifies and validates YAML. It rebuilds your YAML with consistent indentation, optional key sorting and your preferred quote style, and reports syntax errors with the exact line and column. It handles multi-document files and works with Kubernetes, Docker Compose, Ansible and CI/CD configs.
It is made for developers, DevOps engineers and anyone who edits configuration files and wants them clean before a review, commit or deploy. There is nothing to install and no account to create, so you can format YAML on any computer, tablet or phone in seconds.
Your YAML is processed on your device and is never uploaded to Teasoft's servers. That makes it safe to format config files that contain hostnames, internal settings or other sensitive values.