1 KB STL sample file

An STL file of exactly 1,024 bytes. It is a valid STL 3D model (stereolithography) file, generated for this site and checked with an independent parser. Use it wherever you need a 1 KB sample, test or dummy STL file.

sample-stl-1kb.stl

1 KB1,024 bytes

Download 1 KB STL

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Type: model/stl
SHA-256: 422f3ec9537d2ab842888bea96eda122a691cc1c085da2391aa537eba07de146
Direct URL: https://www.sampletestfiles.com/downloads/stl/sample-stl-1kb.stl

What is in this file

One solid of 4 triangles forming a height-field surface, each written as a facet with its normal and three vertices. Blank lines before the closing endsolid statement, which ASCII STL ignores, bring the file to the exact size.

Triangles	4
Encoding	ASCII STL
Solids	1 (terrain)
Units	None: STL has no unit of measurement
Colour and materials	None

How the file begins

The opening lines of sample-stl-1kb.stl, exactly as they appear in the file.

solid terrain
  facet normal -0.1467 0.6125 -0.7767
    outer loop
      vertex 0.0000 0.0000 0.0000
      vertex 0.0000 0.6341 0.5000
      vertex 0.5000 0.1197 0.0000
    endloop
  endfacet
  facet normal -0.1197 0.6298 -0.7675
    outer loop
      vertex 0.5000 0.1197 0.0000
      vertex 0.0000 0.6341 0.5000
      vertex 0.5000 0.7291 0.5000
    endloop

Preview

Shows the file contents.

Where 1 KB matters

The smallest practical test file: 1,024 bytes, small enough to travel in a single network packet. These are the default limits a file of this size is useful for testing:

System	Limit	Note
Ethernet	1,500 bytes (typical MTU)	A 1 KB payload fits in one packet with its headers.
Browser cookies	4,096 bytes per cookie	1 KB is well inside the limit; the 5 KB sample is over it.

All 1 KB sample files

Use this file for

Smoke tests in CI that must run in milliseconds
Testing 3D model upload for print services
Checking detection of ASCII and binary files

Testing notes for STL

A binary file may start with the word "solid" in its free-text header, and many do. Detection has to test whether the file length equals 84 plus 50 bytes for each triangle, not just read the first five bytes.
STL has no unit of measurement. A model drawn in inches and read as millimetres comes out 25 times too small.

STL format reference

Technical details

File name	sample-stl-1kb.stl
Format	STL (STL 3D model (stereolithography))
Extension	.stl
MIME type	model/stl
Size	1,024 bytes (1 KB)
Kind	Text
Signature	73 6F 6C 69 64
SHA-256	422f3ec9537d2ab842888bea96eda122a691cc1c085da2391aa537eba07de146
Created	2026-10-10
Validation	Exact size, signature bytes and structure checked when the file was generated
Preview	Available on this page
Source	Generated for this site; not copied from elsewhere
Licence	Free to use, modify and redistribute (terms)
Category	3D Models

Validated for expected format and integrity. As with any download, scan the file with your own security tools before opening it. How files are made and checked

Download from the command line and verify

Fetch the file with curl, then compare its checksum with the SHA-256 value above.

curl -o sample-stl-1kb.stl 'https://www.sampletestfiles.com/downloads/stl/sample-stl-1kb.stl'
sha256sum sample-stl-1kb.stl     # Linux
shasum -a 256 sample-stl-1kb.stl # macOS

On Windows, run Get-FileHash sample-stl-1kb.stl -Algorithm SHA256 in PowerShell. A matching value proves that the download is complete and unaltered.

Related files

Questions about this file

Is this file exactly 1 KB?: Yes. It is 1,024 bytes, which is 1 KB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
What is inside the 1 KB STL file?: One solid of 4 triangles forming a height-field surface, each written as a facet with its normal and three vertices. Blank lines before the closing endsolid statement, which ASCII STL ignores, bring the file to the exact size.
Are the STL samples ASCII or binary?: The sized samples are ASCII STL, which can be padded to an exact byte count with blank lines. The curated library adds a binary STL file, a unit cube of 12 triangles.

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