20 MB YAML sample

A YAML file of exactly 20,971,520 bytes. It is a valid YAML Ain't Markup Language file, generated by this site. Compare its checksum and test it with the parser used by your application. Use it wherever you need a 20 MB sample, test or dummy YAML file.

sample-yaml-20mb.yaml

20 MB20,971,520 bytes

Download 20 MB YAML

Created in your browser in a few seconds, then checked against the SHA-256 checksum. The file is not uploaded anywhere. No sign-up.

Type: application/yaml
SHA-256: cfeb0f03ba0e2fac8ad16d77dca52c9ebcafcac3adc91ea2eba3fe6a9d6759a5
Delivery: Created in your browser from static generator assets (how it works).

What is in this file

One YAML document with a "records" sequence of 85,957 mappings, each with strings, numbers, booleans, a date, a flow sequence and a nested mapping. Comment lines at the end bring the file to the exact size.

Records	85,957
Documents	1
YAML version	1.2 compatible
Indentation	2 spaces
Encoding	UTF-8 (ASCII characters only)

How the file begins

The opening lines of sample-yaml-20mb.yaml, exactly as they appear in the file.

00000000  23 20 53 61 6d 70 6c 65  54 65 73 74 46 69 6c 65 |# SampleTestFile|
00000010  73 20 73 61 6d 70 6c 65  20 59 41 4d 4c 20 66 69 |s sample YAML fi|
00000020  6c 65 20 28 32 30 20 4d  42 29 0a 2d 2d 2d 0a 67 |le (20 MB).---.g|
00000030  65 6e 65 72 61 74 6f 72  3a 20 53 61 6d 70 6c 65 |enerator: Sample|

Preview

Creates the file in your browser and shows the first 64 KB of it.

Where 20 MB matters

A 20,971,520-byte file: right at the default attachment limit of Outlook, and just under the 25 MB ceilings of Gmail and GitHub web uploads. These are the default limits a file of this size is useful for testing:

System	Limit	Note
Microsoft Outlook	20 MB of attachments by default for internet mail accounts	This file is right at the limit; add a second attachment and it is exceeded.
Gmail	25 MB per message	Under the limit, although email encoding adds about a third in transit.
GitHub web uploads	25 MiB per file added through the browser	Accepted. Pushing with Git allows larger files.
Cloudflare Pages assets	25 MiB per file	The largest round size that can be served as a static asset.
Amazon API Gateway	10 MB payload	Rejected; the upload has to go directly to object storage.
ASP.NET Core (Kestrel)	About 28.6 MB request body by default	Accepted with room for the multipart overhead.

All 20 MB sample files

Use this file for

Finding the first upload limit in a new stack
Testing converters between YAML and JSON
Testing configuration loaders and linters

Testing notes for YAML

Unquoted values are typed by guesswork. In YAML 1.1 parsers the country code NO becomes false, and a version such as 1.10 becomes the number 1.1.
Loading untrusted YAML with a full loader can construct arbitrary objects in some libraries; always use the safe loader.

YAML format reference

Technical details

File name	sample-yaml-20mb.yaml
Format	YAML (YAML Ain't Markup Language)
Extension	.yaml
MIME type	application/yaml
Size	20,971,520 bytes (20 MB)
Kind	Text
SHA-256	cfeb0f03ba0e2fac8ad16d77dca52c9ebcafcac3adc91ea2eba3fe6a9d6759a5
Created	2026-10-23
Validation	See the listed size and SHA-256. Small downloads are checked in the browser; verify streamed downloads manually. A hash match does not prove parser compatibility.
Preview	Available on this page
Source	Generated in your browser by this site's generator; not copied from elsewhere
Licence	Free to use, modify and redistribute (terms)
Category	Configuration

Check the stated structure and checksum against your application requirements. As with any download, scan the file with your own security tools before opening it. How files are made and checked

Verify your copy

This file is created in your browser, so it has no direct URL for curl or wget. The generator is designed to produce reproducible bytes. After saving, compare the checksum with the SHA-256 value above.

sha256sum sample-yaml-20mb.yaml     # Linux
shasum -a 256 sample-yaml-20mb.yaml # macOS

On Windows, run Get-FileHash sample-yaml-20mb.yaml -Algorithm SHA256 in PowerShell. For scripts and pipelines, save the file once and keep your own copy.

Related files

Questions about this file

Is this file exactly 20 MB?: Yes. It is 20,971,520 bytes, which is 20 MB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
What is inside the 20 MB YAML file?: One YAML document with a "records" sequence of 85,957 mappings, each with strings, numbers, booleans, a date, a flow sequence and a nested mapping. Comment lines at the end bring the file to the exact size.
Are the samples a single YAML document?: Yes. Each file is one document with a top-level mapping and a sequence of records.

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