- Are my photos uploaded to a server?
- No. Everything runs inside your web browser using the File API and Canvas API. Your photos never leave your device — they are read into browser memory, rendered on an HTML canvas, converted to a PDF using the pdf-lib JavaScript library, and downloaded directly to your computer. There is no server involved at any step.
- What paper size should I choose for a home printer?
- Most home printers in North America use Letter (8.5 × 11 in). Select A4 if you are in Europe or Asia. For photo lab prints, choose 4×6 (postcard size, the default for most photo printing services) or 5×7 for slightly larger prints. Print the PDF at 100% scale (no "fit to page") to get the correct physical dimensions.
- How many photos can I add, and what happens if I have more than the grid cells?
- You can add as many photos as you like — the tool keeps them in order. The collage places one photo per cell, left-to-right then top-to-bottom. If you have more photos than cells (columns × rows), the extras are simply not shown in this layout. Increase the column or row count to fit more photos. If you have fewer photos than cells, the remaining cells are left white.
- Why does my photo appear cropped in the collage?
- Each cell uses "cover fit" — the photo is scaled so it fills the cell entirely, and any overflow is cropped from the centre. This avoids white bars and ensures a clean grid appearance. If you want a specific portion visible, crop the photo to roughly the right aspect ratio before adding it.
- What resolution should I use for printing?
- 300 dpi is the standard for home and professional photo printing — it produces sharp detail with no visible pixels at normal viewing distance. Use 150 dpi for quick web-sharing previews or if you need a smaller file size. The canvas pixel dimensions are exactly (paper width in inches × dpi) by (paper height in inches × dpi), so a 300 dpi Letter PDF is 2550 × 3300 pixels.