Image to PDF

About Image to PDF

This Image to PDF tool converts images (PNG, JPEG, WebP) into PDF pages using client-side JavaScript processing. Each uploaded image is added as a separate PDF page and automatically scaled to fit within the page margins while preserving the original aspect ratio.

The conversion uses the jsPDF library to embed image data directly into the PDF structure, then generates a downloadable file without any server upload or processing.

PDF Image Embedding Process

When an image is added to a PDF, the following steps occur:

1. Image Loading: The image file is read as a Data URL (base64-encoded binary data)
2. Format Detection: The MIME type prefix (data:image/png or data:image/jpeg) determines the PDF encoding method
3. Dimension Calculation: Original width and height are measured to compute aspect ratio
4. Page Scaling: The image is scaled to fit the target page size while maintaining proportions
5. PDF Object Creation: A new page is added and the image is embedded as an XObject
6. File Generation: All objects are serialized into the binary PDF format with proper headers and cross-reference tables

Supported Image Formats

Page Size Reference

Aspect Ratio Preservation

To prevent image distortion, the tool calculates a uniform scale factor:

// Calculate scale to fit image within page bounds
const maxWidth = pageWidth - (2 * margin);
const maxHeight = pageHeight - (2 * margin);
const scaleX = maxWidth / imageWidth;
const scaleY = maxHeight / imageHeight;
const scale = Math.min(scaleX, scaleY); // Use smaller scale

const renderWidth = imageWidth * scale;
const renderHeight = imageHeight * scale;
const x = (pageWidth - renderWidth) / 2; // Center horizontally
const y = (pageHeight - renderHeight) / 2; // Center vertically

Common Use Cases

• Document Scanning: Combine multiple scanned pages into a single PDF file
• Photo Albums: Create printable photo collections or portfolios
• Screenshot Reports: Document bugs or workflows with sequenced screenshots
• Receipt Organization: Compile expense receipts for reimbursement
• Art Portfolios: Assemble artwork images for submission or sharing
• Print Preparation: Convert digital images to print-ready PDF format
• Archive Creation: Preserve visual content in a standardized, long-term format

PDF File Size Considerations

PDF file size depends on image resolution, format, and compression:

• High-resolution images: Larger file sizes but better print quality. Consider downsampling for screen-only viewing.
• JPEG quality: Lower quality (60-80%) reduces file size significantly with minimal visible loss for photos.
• PNG optimization: PNG files can be large for photographs but are efficient for graphics with few colors.
• Page count: Each additional page adds overhead but the image data dominates total size.

jsPDF Library Usage

// Initialize PDF with A4 size, portrait orientation, points unit
const pdf = new jsPDF('p', 'pt', 'a4');

// Add first image
pdf.addImage(imageData, 'PNG', x, y, width, height);

// Add additional pages
pdf.addPage();
pdf.addImage(nextImageData, 'JPEG', x, y, width, height);

// Save the generated PDF
pdf.save('document.pdf');

Browser Compatibility

This tool uses modern JavaScript features and requires:

• File API: For reading uploaded image files (all modern browsers)
• Blob API: For generating downloadable PDF files
• Promise support: For async image loading
• Canvas API: Used internally by jsPDF for image processing

Tested on Chrome 60+, Firefox 55+, Safari 11+, Edge 79+.