File compatibility: what we test
Last reviewed November 9, 2026
Every product build goes through automated checks before release. This page lists the tools those checks use for each file format, the apps we have not opened the files in, and the limits we know about. We only name an app as tested when a file was actually opened in it.
In short: spreadsheet formulas are recalculated in LibreOffice Calc and documents are rendered in LibreOffice Writer. Seven spreadsheets were also checked in Google Sheets (listed below). We have not tested the files in Microsoft Excel, Microsoft Word, Google Docs, Apple Numbers or Apple Pages, or any other spreadsheet in Google Sheets.
Spreadsheets checked in Google Sheets
Checked on November 9, 2026. Each XLSX file was uploaded to Google Drive with conversion to Google Sheets, which recalculates every formula on import; the results Google Sheets displayed were compared with the factory's independently calculated expected values (or, for the free roofing calculator, with every LibreOffice-recalculated formula cell). Drop-down lists, cell highlighting (conditional formatting) and editing were not checked in Google Sheets.
| Product | File (version checked) | Results matched |
|---|---|---|
| Free Roofing Calculator | Free-Roofing-Calculator.xlsx (v1.0.3) | 11 of 11 |
| Free Monthly Budget Starter | Monthly-Budget-Starter.xlsx (v1.0.3) | 18 of 18 |
| Debt Repayment Tracker | Debt-Repayment-Tracker.xlsx (v1.0.3) | 12 of 12 |
| Student Assessment Tracker | Student-Assessment-Tracker.xlsx (v1.0.3) | 4 of 4 |
| Activity Progress Tracker | Activity-Progress-Tracker.xlsx (v1.0.3) | 4 of 4 |
| Roofing Estimate Calculator | Roofing-Estimate-Calculator.xlsx (v1.0.3) | 5 of 5 |
| Job Application Tracker | Job-Application-Tracker.xlsx (v1.0.3) | 5 of 5 |
| Format | Checked with | Not tested in |
|---|---|---|
| Printable PDF (.pdf) | pypdf and poppler (page size, fonts, every page rendered) | Adobe Acrobat Reader, Apple Preview, Browser PDF viewers (Chrome, Edge, Safari, Firefox), Tablet note-taking apps (for example GoodNotes or Notability), Printing on a physical printer |
| Spreadsheet (.xlsx) | LibreOffice Calc (recalculation, expected values) and openpyxl | Microsoft Excel (any version, desktop, web or mobile), Google Sheets, Apple Numbers |
| Editable document (.docx) | LibreOffice Writer (rendering) and python-docx (structure) | Microsoft Word (any version, desktop, web or mobile), Google Docs, Apple Pages |
| Vector graphic (.svg) | XML parser and cairosvg (rendering) | Figma, Adobe Illustrator, Affinity Designer, Inkscape, Canva, Website builders |
| Image (.png) | Pillow (size, transparency, match with the SVG source) | Canva, Google Slides, Microsoft Word, GoodNotes, Notability, Image editors |
Printable PDF (.pdf)
What we check
- Opened and parsed with pypdf: page count and page size (US Letter 8.5 × 11 in or A4) checked on every page.
- Fonts checked as embedded with poppler's pdffonts.
- Every page rendered to an image with poppler's pdftoppm and checked for blank pages and content outside the printable safe area.
Not tested
- Adobe Acrobat Reader
- Apple Preview
- Browser PDF viewers (Chrome, Edge, Safari, Firefox)
- Tablet note-taking apps (for example GoodNotes or Notability)
- Printing on a physical printer
Known limits
- PDFs are flat pages: no fillable form fields and no hyperlinked tabs.
- Page sizes are verified in the file, not by printing. Print at 100% ("Actual size") on the paper size in the file name.
Spreadsheet (.xlsx)
What we check
- Recalculated in LibreOffice Calc (headless) and every cell checked for formula errors.
- Expected-value tests: specific formula cells compared with values worked out independently, after recalculation in LibreOffice.
- Blank-input and zero-input copies recalculated to catch errors in an empty workbook.
- Read with openpyxl to check sheets, formulas and the Start Here sheet.
Not tested
- Microsoft Excel (any version, desktop, web or mobile)
- Google Sheets
- Apple Numbers
Known limits
- Formula results are verified in LibreOffice Calc only. We have not confirmed they recalculate identically in Excel, Google Sheets or Numbers.
- Formatting, data validation and sheet protection may behave differently in apps we have not tested.
Editable document (.docx)
What we check
- Opened with python-docx: headings, tables, fill-in fields (content controls and checkboxes) and page size checked.
- Document XML checked for the element order the Office Open XML schema requires.
- Rendered to PDF in LibreOffice Writer: page size, page count and no blank pages; the embedded Inter font is used even with system fonts hidden.
Not tested
- Microsoft Word (any version, desktop, web or mobile)
- Google Docs
- Apple Pages
Known limits
- Page counts are as laid out in LibreOffice Writer; other apps may differ by a page.
- Fill-in fields and checkboxes were checked in the file structure, not by typing into them in Word, Google Docs or Pages.
- Apps that don't support embedded fonts substitute a similar font.
Vector graphic (.svg)
What we check
- Parsed as well-formed XML with the expected viewBox.
- Checked self-contained: no embedded raster images, scripts or external references.
- Rendered with cairosvg to confirm it draws.
Not tested
- Figma
- Adobe Illustrator
- Affinity Designer
- Inkscape
- Canva
- Website builders
Known limits
- Rendering is verified with cairosvg only. Import and editing in design apps were not tested.
Image (.png)
What we check
- Opened with Pillow: valid PNG, stated pixel size and transparency.
- Compared pixel by pixel with a fresh render of its SVG source.
Not tested
- Canva
- Google Slides
- Microsoft Word
- GoodNotes
- Notability
- Image editors
Known limits
- Use in other apps (for example as planner stickers) was not tested.
Downloads and packaging
- Every download includes LICENCE.txt. Products with more than one file also include a ZIP of all files (CRC checked; each member is byte-identical to a listed file).
- On 9 November 2026 we confirmed that every current file of every published product is in storage at its recorded size, and that each product's files match the formats listed on its page.
Per product and version
Each product page lists its formats, file count and version, and its Compatibility box repeats the checks that apply to those formats. The checks run again for every new version before it is published; a product's version history shows when its files last changed.
If a file doesn't work in your app
Tell us which app and version you used. We'll help, fix the file or refund you under our refund policy. Contact support, email downloads@brainfystudio.com or read the FAQ.