File formats

Choose the right format for your use case

The API supports four output formats:

• PNG (default)
• JPG
• WebP
• PDF

To specify a format, add the appropriate file extension to your image URL:

Format	Example URL	Best For
PNG	https://hcti.io/v1/image/abc123.png	Screenshots, images with transparency
JPG	https://hcti.io/v1/image/abc123.jpg	Photos, complex images with no transparency
WebP	https://hcti.io/v1/image/abc123.webp	Modern web applications, optimal compression
PDF	https://hcti.io/v1/image/abc123.pdf	Documents, invoices, printable content

• Lossless compression
• Supports transparency
• Larger file size
• Best for:
  • Screenshots
  • Images with text
  • Graphics with sharp edges
  • Content requiring transparency

• Lossy compression
• No transparency support
• Smaller file size
• Best for:
  • Photographs
  • Complex images
  • When transparency isn’t needed
  • When smaller file size is priority

• Modern format
• Supports transparency
• Superior compression
• Best for:
  • Web applications
  • Progressive loading
  • Optimal performance
  • Modern browsers

• Document format
• Vector-based rendering
• Ideal for printing
• Best for:
  • Invoices and receipts
  • Certificates
  • Reports
  • Printable documents
• Use the pdf_options parameter for customization (Learn more)

All paid accounts receive automatic WebP optimization:

1. Our edge servers detect the user’s browser capabilities
2. If WebP is supported, images are automatically served in WebP format
3. Fallback formats are served for non-supporting browsers

Benefits:

• Improved page load times
• Better SEO scores
• Reduced bandwidth usage
• No code changes required

1. Default to PNG for:

   • Screenshots
   • Text-heavy images
   • When quality is critical

2. Use JPG for:

   • Photos
   • Complex images
   • When file size is priority

3. Enable WebP for:

   • Modern web applications
   • Performance optimization
   • Progressive enhancement

Format	Chrome	Firefox	Safari	Edge	IE11
PNG	✅	✅	✅	✅	✅
JPG	✅	✅	✅	✅	✅
WebP	✅	✅	✅	✅	❌
PDF	✅	✅	✅	✅	✅

Need help?

Talk to a human. Email support@htmlcsstoimage.com and we’ll help you get started.