Sirv Dynamic Imaging API

Transform images on-the-fly by adding URL parameters.

Base URL: https://yourcdn.sirv.com/path/image.jpg?{options}

Quick Reference

Sizing

Option	Example	Description
w	?w=800	Width (px or %)
h	?h=600	Height (px or %)
s	?s=500	Longest dimension
thumbnail	?thumbnail=200	Square thumbnail
scale.option	?scale.option=fit	fit, fill, ignore, noup

?w=800                    # 800px wide
?w=50%                    # 50% of original width
?w=800&h=600              # Specific dimensions
?w=800&scale.option=fit   # Fit within 800px (maintain aspect)
?w=800&scale.option=fill  # Fill 800px (may crop)

Cropping

Option	Example	Description
cw, ch	?cw=500&ch=300	Crop width/height
cx, cy	?cx=100&cy=50	Crop start position
crop.type	?crop.type=face	Auto-crop: trim, poi, face

?cw=500&ch=300&cx=100&cy=50   # Manual crop
?crop.type=face&w=400          # Face detection crop
?crop.type=trim                # Trim whitespace

Format & Quality

Option	Example	Description
format	?format=webp	jpg, png, webp, avif, optimal
q	?q=85	JPEG quality 0-100
webp-fallback	?webp-fallback=jpg	Fallback for non-WebP browsers

?format=webp&q=80           # WebP at 80% quality
?format=optimal             # Auto-select best format
?format=avif                # AVIF format

Effects

Option	Range	Description
blur	0-100	Gaussian blur
sharpen	0-100	Sharpen
brightness	-100 to 100	Brightness
contrast	-100 to 100	Contrast
saturation	-100 to 100	Saturation
grayscale	true/false	Black & white
rotate	-180 to 180	Rotation degrees
colortone	preset name	sepia, warm, cold, sunset...

?blur=10                    # Light blur
?grayscale=true&contrast=20 # B&W with more contrast
?colortone=sepia            # Sepia effect
?rotate=90                  # Rotate 90 degrees

Text Overlay

?text=Hello%20World
?text=Hello&text.size=30%&text.color=white&text.position=southeast
?text=©2024&text.font.family=Open%20Sans&text.opacity=50

Watermark

?watermark=/logo.png
?watermark=/logo.png&watermark.position=southeast&watermark.opacity=50
?watermark=/logo.png&watermark.scale.width=20%

Canvas & Frame

?canvas.width=1200&canvas.height=800&canvas.color=white
?frame.style=solid&frame.color=black&frame.width=10

Common Patterns

Responsive srcset

<img
  src="https://cdn.sirv.com/image.jpg?w=800"
  srcset="
    https://cdn.sirv.com/image.jpg?w=400 400w,
    https://cdn.sirv.com/image.jpg?w=800 800w,
    https://cdn.sirv.com/image.jpg?w=1200 1200w
  "
  sizes="(max-width: 600px) 100vw, 50vw"
  alt="Description"
>

Modern format with fallback

<picture>
  <source srcset="https://cdn.sirv.com/image.jpg?format=avif" type="image/avif">
  <source srcset="https://cdn.sirv.com/image.jpg?format=webp" type="image/webp">
  <img src="https://cdn.sirv.com/image.jpg" alt="Description">
</picture>

Product thumbnail

?w=400&h=400&scale.option=fit&canvas.width=400&canvas.height=400&canvas.color=white

Watermarked download

?watermark=/logo.png&watermark.position=southeast&watermark.opacity=30&dl

When to Read Reference Files

• Sizing & cropping (scale options, crop modes, canvas): See sizing.md
• Effects & filters (color, blur, sharpen, colortone presets): See effects.md
• Text & watermarks (fonts, positioning, styling): See overlays.md
• Profiles & optimization (reusable presets, caching, formats): See profiles.md

Processing Order

1. Auto-crop
2. Scale
3. Crop
4. Canvas
5. Rotate
6. Other effects

Profiles

Save reusable option sets as JSON profiles in /Profiles/:

?profile=my-thumbnail

Profile example:

{
  "image": {
    "scale": {"width": 400},
    "format": "webp",
    "quality": 80
  }
}