500 KB JS sample

A JS file of exactly 512,000 bytes. It is a valid JavaScript source file file, generated by this site. Compare its checksum and test it with the parser used by your application. Use it wherever you need a 500 KB sample, test or dummy JS file.

sample-js-500kb.js

500 KB512,000 bytes

Download 500 KB JS

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: text/javascript
SHA-256: 7eb94d74c9e1ea1835c2570e294596e4b0b4115e17562b2a49fbf0983500de9c
Delivery: Created in your browser from static generator assets (how it works).

What is in this file

Strict-mode JavaScript that declares an array of 4,133 record objects and two helper functions, and runs nothing when loaded. Comment lines at the end bring the file to the exact size.

Records	4,133
Functions	2 (totalBalance, findById)
Module format	Script, with a CommonJS export when available
Dependencies	None
Encoding	UTF-8 (ASCII characters only)

How the file begins

The opening lines of sample-js-500kb.js, exactly as they appear in the file.

00000000  2f 2f 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 4a 61 76 61 53 63 |es sample JavaSc|
00000020  72 69 70 74 20 66 69 6c  65 20 28 35 30 30 20 4b |ript file (500 K|
00000030  42 29 0a 2f 2f 20 50 6c  61 69 6e 20 45 43 4d 41 |B).// Plain ECMA|

Preview

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

Where 500 KB matters

A 512,000-byte file: larger than most API body limits, smaller than most upload limits. These are the default limits a file of this size is useful for testing:

System	Limit	Note
Amazon DynamoDB items	400 KB per item	500 KB cannot be stored as a single item.
Express body parsers	100 KB by default	Rejected unless the limit is raised.
nginx request body	1 MB by default (client_max_body_size)	Accepted with room to spare.

All 500 KB sample files

Use this file for

Checking email size handling
Testing static asset delivery and caching
Testing bundlers and minifiers with large inputs

Testing notes for JS

Never execute an uploaded script. Treat .js uploads as text to be stored or analysed.
The old types application/javascript and application/x-javascript are obsolete; text/javascript is the registered type.

JS format reference

Technical details

File name	sample-js-500kb.js
Format	JS (JavaScript source file)
Extension	.js
MIME type	text/javascript
Size	512,000 bytes (500 KB)
Kind	Text
SHA-256	7eb94d74c9e1ea1835c2570e294596e4b0b4115e17562b2a49fbf0983500de9c
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-js-500kb.js     # Linux
shasum -a 256 sample-js-500kb.js # macOS

On Windows, run Get-FileHash sample-js-500kb.js -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 500 KB?: Yes. It is 512,000 bytes, which is 500 KB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
What is inside the 500 KB JS file?: Strict-mode JavaScript that declares an array of 4,133 record objects and two helper functions, and runs nothing when loaded. Comment lines at the end bring the file to the exact size.
Does the sample script do anything when loaded?: No. It defines an array and two functions and has no side effects.

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