Free PPTX test files and sample generator
Microsoft PowerPoint's Open XML presentation format. Slides with text, images and layouts.
What is a .pptx file?
PPTX: PowerPoint Presentation. PPTX is the modern PowerPoint deck, again a ZIP of XML parts, with one part per slide. Presentation files tend to be large and image-heavy, which makes them a good stress test for upload and preview paths.
Why generate a test PPTX file?
- Test deck upload, thumbnail generation or slide-count extraction.
- Check handling of multi-slide decks and embedded images.
- Exercise size limits with a large presentation.
What you can put inside a .pptx file
You get 5 content options for PPTX, so the file holds something meaningful rather than random padding: Title + bullets, Text-heavy, Image, Bar chart, Pie chart. Pick several and they are merged into one file, with a section, sheet, slide or folder for each.
How a .pptx file is identified
Every .pptx file begins with 50 4B 03 04, the ASCII letters "PK", the initials of Phil Katz, who created the ZIP format. That is what a validator inspecting content rather than the file name looks for.
How the size lands on the exact byte
The package is a ZIP, so the padding is trailing whitespace inside one of the XML parts it already contains. Extractors and Office readers both ignore it, so the document opens unchanged.
Negative testing with broken PPTX files
- Invalid. Identifiable, but wrong inside, so it fails during parsing.
- Corrupted. The leading bytes are destroyed, so the
50 4B 03 04identifying a .pptx is gone. Same length as the valid file. - Incomplete. Truncated part-way, so it is genuinely shorter.
- Empty. Chosen under Content rather than File Condition: valid structure, no data.
Which failure to reach for, and what to assert for each, is covered in how to make a corrupted file for testing. For upload limits and type checks see testing file upload validation.
Sample PPTX content
[Presentation], Slide 1: Title | Slide 2: Chart | Slide 3: Summary
This shows the shape of the file. Your download is generated fresh at the size you choose, so the values will differ.
How to open and verify the file
Open in PowerPoint, LibreOffice Impress or Google Slides.
Media type application/vnd.openxmlformats-officedocument.presentationml.presentation · extension .pptx · category Doc & TXT
Generate a .pptx file → · questions about sizes, privacy or cost are answered on the site FAQ.
Frequently asked questions about PPTX files
What identifies a .pptx file?
A .pptx file begins with the bytes 50 4B 03 04, the ASCII letters "PK", the initials of Phil Katz, who created the ZIP format. Those bytes are what a content-sniffing validator looks for, and what the Corrupted condition destroys.
How can a .pptx file be an exact number of bytes?
The package is a ZIP, so the padding is trailing whitespace inside one of the XML parts it already contains. Extractors and Office readers both ignore it, so the document opens unchanged.
What can go inside the PPTX file?
There are 5 content options for .pptx: Title + bullets, Text-heavy, Image, Bar chart, Pie chart. Choose more than one and they are combined into a single file, a section, sheet, slide or folder per option, rather than downloaded separately.
Can I download several broken PPTX files at once?
Yes, select more than one File Condition and you get one ZIP containing a .pptx per condition, each named after its condition.
Can the PPTX file use UTF-16 or a byte-order mark?
No, and deliberately. A .pptx file is a container rather than plain text, so rewriting its bytes as UTF-16 would not produce a UTF-16 document. It would produce a broken file. Use a text format such as CSV, JSON or XML for encoding tests.
How do I open or verify the PPTX file?
Open in PowerPoint, LibreOffice Impress or Google Slides.