A Guide to Image to PDF Compilation

Compiling multiple raster photos into a single Portable Document Format (PDF) is a common workspace task. Converting images locally avoids exposing confidential visual reports, scanned receipts, or design assets to external servers, keeping your files completely private.

Understanding Page Size Dimensions

Selecting the right page layout ensures your document prints and renders correctly on other devices:

• Fit to Image Size: Each PDF page perfectly matches the pixel dimensions of its source photo. Best for photo albums, portfolios, and presentations with no white space.
• A4 Paper (210 × 297 mm): International standard for business reports, contracts, and letters. Equivalent to 595 × 841 points in PDF coordinates.
• US Letter (8.5 × 11 in): The standard format in North America for academic essays, office printing, and receipts. Equivalent to 612 × 792 points.

Scaling, Fitting, and Margin Settings

Placing pixel-based images onto standard paper layouts requires clear scaling rules:

• Contain: Scales the image proportionally to fill the printable area without cropping. The aspect ratio is always preserved, leaving small strips of white space if ratios differ.
• Stretch: Forces the image to fill the entire printable area. Aspect ratio is sacrificed, which works well for background tiles and pattern fills.
• Margins: Adds clean negative-space borders. Small margins (20 pt ≈ 7 mm) or medium margins (40 pt ≈ 14 mm) prevent content from touching paper edges during printing.

How Client-Side PDF Generation Works

InstConvert does not use a remote server to compile PDFs. When you click Generate PDF, the FileReader API loads each image into the browser's volatile memory. An HTML5 Canvas compresses and renders each page with the correct margins and scaling. Finally, the jsPDF library assembles the binary PDF stream and triggers a local download — no data ever leaves your device.