3 MB CSS sample
A CSS file of exactly 3,145,728 bytes. It is a valid Cascading Style Sheets file, generated by this site. Compare its checksum and test it with the parser used by your application. Use it wherever you need a 3 MB sample, test or dummy CSS file.
Download
sample-css-3mb.css
3 MB3,145,728 bytes
Download 3 MB CSSCreated in your browser in a few seconds, then checked against the SHA-256 checksum. The file is not uploaded anywhere. No sign-up.
- Type
- text/css
- SHA-256
8431f869313a45b5cbe3a2bf866478dd46cf1d3b9c0adad7f4332e4c6f3f270c- Delivery
- Created in your browser from static generator assets (how it works).
What is in this file
A custom property block, a body rule and 31,775 class rules with colours, margins, padding and border radii. A comment at the end brings the file to the exact size.
| Rules | 31,777 |
|---|---|
| Custom properties | 2 |
| Imports | None |
| Encoding | UTF-8 (ASCII characters only) |
How the file begins
The opening lines of sample-css-3mb.css, exactly as they appear in the file.
00000000 2f 2a 20 53 61 6d 70 6c 65 54 65 73 74 46 69 6c |/* SampleTestFil|
00000010 65 73 20 73 61 6d 70 6c 65 20 43 53 53 20 66 69 |es sample CSS fi|
00000020 6c 65 20 28 33 20 4d 42 29 20 2a 2f 0a 3a 72 6f |le (3 MB) */.:ro|
00000030 6f 74 20 7b 0a 20 20 2d 2d 69 6e 6b 3a 20 23 31 |ot {. --ink: #1|Preview
Creates the file in your browser and shows the first 64 KB of it.
Where 3 MB matters
A 3,145,728-byte file, 3 MB in the binary units that operating systems and upload limits use. It is useful wherever a form, an API gateway, a storage quota or a mail server is configured with a limit of about this size.
Use this file for
- Finding the first upload limit in a new stack
- Testing code editors and syntax highlighters
- Testing minifiers and bundlers
Testing notes for CSS
- With X-Content-Type-Options: nosniff, browsers refuse a stylesheet that is not served as text/css.
Technical details
| File name | sample-css-3mb.css |
|---|---|
| Format | CSS (Cascading Style Sheets) |
| Extension | .css |
| MIME type | text/css |
| Size | 3,145,728 bytes (3 MB) |
| Kind | Text |
| SHA-256 | 8431f869313a45b5cbe3a2bf866478dd46cf1d3b9c0adad7f4332e4c6f3f270c |
| 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 | Code |
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-css-3mb.css # Linux
shasum -a 256 sample-css-3mb.css # macOSOn Windows, run Get-FileHash sample-css-3mb.css -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 3 MB?
- Yes. It is 3,145,728 bytes, which is 3 MB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
- What is inside the 3 MB CSS file?
- A custom property block, a body rule and 31,775 class rules with colours, margins, padding and border radii. A comment at the end brings the file to the exact size.
- What do the sample stylesheets contain?
- Custom properties, a body rule and a long list of class rules, with no @import rules or external URLs.