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XLSX generator

File size Unit

1 MB

Download Sample XLSX Files for Excel Testing

Q: What MIME type should I use to validate an XLSX file?

The standard MIME type is application/vnd.openxmlformats-officedocument.spreadsheetml.sheet. For stronger validation, do not rely on the MIME type or file extension alone. Check the file structure and apply the validation rules required by your application.

Download free sample XLSX files from 3 KB to 100 MB for Excel upload testing, spreadsheet imports, file validation, and previews. Choose your preferred file size and get a ready-to-use Excel test file instantly.

Download XLSX

Choose a Sample Excel File by Size

Select a sample XLSX file based on the file size your application needs to handle. Testing multiple sizes can help identify upload restrictions, processing delays, and failures near configured limits.

File Size	Suggested Testing Use
3 KB	Small-file acceptance and basic validation
10 KB	Lightweight spreadsheet uploads
100 KB	Standard form and API upload checks
500 KB	Medium-sized file handling
1 MB	Routine spreadsheet import testing
5 MB	Larger workbook uploads and previews
10 MB	Import performance and processing checks
25 MB	Large-file handling and timeout testing
50 MB	High-volume upload and worker testing
100 MB	Maximum-size boundary and resource testing

Choose the size closest to your application's expected workload. For upload-limit testing, also test files immediately below and above your configured limit.

What's Inside a Sample XLSX File?

An XLSX file is an Excel workbook saved using the Office Open XML format. It is a structured file package rather than a plain text document.

XLSX workbooks are commonly used to store tabular information for reporting, business operations, data analysis, and application imports. Software may read workbook structure, identify worksheets, extract cell values, and convert spreadsheet content into another format.

Testfilelab's sample XLSX files are intended for file handling and testing workflows. Before using a generated workbook to test a specific number of rows, worksheet count, formulas, or data-import rules, inspect its actual contents and confirm that they match your test requirements. File size alone does not confirm the amount or type of spreadsheet data inside a workbook.

XLSX

sample-10kb.xlsx 1 worksheet · 1 cell (A1) · 10,240 bytes

[Content_Types].xml 571 B
_rels/.rels 300 B
xl/workbook.xml 296 B
xl/_rels/workbook.xml.rels 301 B
xl/worksheets/sheet1.xml 295 B
xl/media/filler.bin 7,771 B

Worksheet data Internal padding

Common Reasons to Use a Sample XLSX File

Application development

Check whether a web application accepts Excel workbook uploads.

Data import testing

Test the file-selection and import process before using real datasets.

Preview testing

Confirm that your application can open or display an XLSX file.

API testing

Validate file upload endpoints and multipart form-data handling.

Quality assurance

Check file-size limits, error handling, and processing behavior.

Performance testing

Compare how your system handles smaller and larger workbook files.

XLSX File Technical Details

Knowing the technical properties of an XLSX file helps developers build more reliable file validation and processing workflows.

Property	Value
File extension	`.xlsx`
File format	Office Open XML spreadsheet workbook
MIME type	`application/vnd.openxmlformats-officedocument.spreadsheetml.sheet`
File signature	ZIP-based package signature commonly beginning with PK
Available size range	3 KB to 100 MB
Typical applications	Microsoft Excel, LibreOffice Calc, and compatible spreadsheet software

What Does the XLSX File Signature Mean?

An XLSX file uses a ZIP-based package structure to store workbook components. Its opening bytes commonly begin with the characters PK, represented by the hexadecimal signature 50 4B.

This signature is useful during file inspection, but it is not enough to establish that a file is a valid Excel workbook. Other ZIP-based formats can share the same initial signature.

For reliable validation, check the expected XLSX MIME type and inspect the package structure. Where appropriate, confirm that the package contains the required workbook components and can be opened by a compatible spreadsheet reader.

MIME type reference: XLSX MIME type details

First bytes of the file

50 P 4B K 03 · 04 ·

Files that start the same way

XLSX Excel workbook 50 4B … DOCX Word document 50 4B … ZIP Plain ZIP archive 50 4B …

Check the MIME type and package contents to tell them apart.

What Can You Test With a Sample XLSX File?

A sample Excel file is useful for testing several parts of a file-handling workflow. Select scenarios that match your application's actual requirements.

1. Excel File Upload Limits

Upload XLSX files at different sizes to confirm that your application enforces its configured limits. Test files below, at, and above the maximum permitted size.

Check both client-side and server-side validation. A file rejected by the interface should also be handled correctly by the backend.

2. Spreadsheet Import Workflows

Use a sample XLSX file to test the steps involved in selecting, uploading, and processing a workbook. Confirm that the application returns clear success or failure messages and handles unsupported files correctly.

For row-count, column-mapping, formula, or worksheet-specific tests, verify that the workbook contains the exact data structure your test requires.

3. Excel Preview and Rendering

Test whether your application can display an uploaded workbook or generate a preview. Check loading behavior, error messages, and what happens when the preview service cannot process a file.

A successful upload does not automatically mean the workbook will render correctly.

4. API and Automated Testing

Use XLSX files in API requests and automated test suites to check file upload endpoints, response codes, validation rules, and processing outcomes.

Keep the test file size and expected response consistent so that results can be compared across environments.

5. Large-File Processing and Timeouts

Larger files can expose limits that small test files do not reveal. Test processing time, memory use, request timeouts, and background-worker behavior with appropriately sized XLSX files.

Use the 50 MB and 100 MB options only in environments configured to handle those sizes.

50 MB XLSX 100 MB XLSX

Download a Sample XLSX File From the Command Line

You can download a generated XLSX file with curl instead of using the browser interface. This is useful for local testing, scripts, and continuous integration workflows.

This example requests the 1 MB XLSX file. Replace 1mb with another supported size when you need a different test file.

You can use the downloaded file in a local test, an upload request, or a controlled QA workflow. Confirm the returned file and its actual size before using it as a strict test fixture.

terminal

$ curl -L -o sample-1mb.xlsx "https://www.testfilelab.com/docs/generate/xlsx/1mb?download=1"

Understanding XLSX File Sizes

File-size labels can use decimal or binary units. This difference matters when testing exact upload limits.

Decimal 1 MB = 1,000,000 bytes
Binary 1 MiB = 1,048,576 bytes
Binary 100 MiB = 104,857,600 bytes

An application may display a file size differently from the value used by its backend. When testing an exact boundary, compare the actual byte count with the limit configured by your application.

1 MB (decimal) 1,000,000 bytes

1 MiB (binary) 1,048,576 bytes

+48,576 bytes difference

For a separate conversion tool, visit the File Size Converter.

Frequently Asked Questions

You can choose a sample Excel workbook from the size options on this page. Select the required size and download the file for your upload, preview, or processing tests.

No. XLSX is the Office Open XML workbook format, while XLS is an older Excel workbook format. Applications may handle them differently, so test the specific extension and format your system supports.

Do not assume a particular number of rows, columns, worksheets, or formulas based on the file size. Inspect the generated workbook and confirm its actual contents before using it for data-dependent import tests.

The standard MIME type is application/vnd.openxmlformats-officedocument.spreadsheetml.sheet. For stronger validation, do not rely on the MIME type or file extension alone. Check the file structure and apply the validation rules required by your application.

Yes. Select files of different sizes to check upload restrictions, server-side validation, processing time, and error handling. For boundary tests, include files below, at, and above your configured maximum.

Explore More Sample Test Files

Choose another format if your application supports multiple document types.

PDF Sample PDF files For PDF workflows DOCX Sample DOCX files For Word document uploads DOC Sample DOC files For legacy Word document testing TXT Sample TXT files For plain-text processing MD Sample Markdown files For Markdown parsing XML Sample XML files For structured text processing All sample document formats To explore the available document files File upload testing guide For upload validation scenarios File validation testing guide For file-checking workflows XLSX MIME type details For format identification

Download Your Sample XLSX File

Get a sample XLSX file for your next upload, spreadsheet preview, or file-processing test. Choose the size that matches your scenario, download the workbook, and use it to test your application under controlled conditions.