In technical terms, what you are doing is called URL Manipulation or URL Parameter Tuning.
When you specifically change the parts after the ?, you are modifying Query Parameters (also known as Query Strings).
Here is a breakdown of what’s happening and the different names for this practice:
1. URL Parameter Manipulation
This is the most accurate term for what you’re doing. A URL is often broken down into the base path and the “parameters” that tell the server how to serve the file.
- The Key: format
- The Value: webp
By changing the value to jpg, you are sending a different request to the server’s API.
2. Hot-swapping (Informal)
In web development circles, quickly changing a value in the address bar to see how the page or image reacts is often called “hot-swapping” or “manual fetching.” It’s a common way to test if a website supports different image sizes or types without using a dedicated tool.
3. Dynamic Image Resizing/Formatting
From the perspective of the server (the cdn.cosmos.so part), this is called Dynamic Transformation. Instead of storing thousands of different versions of one photo, the server uses those URL instructions to convert the image “on the fly” before sending it to your screen.
---
Common Parameters You Can Often “Hack”
If a URL looks like yours, you can often experiment with these other common keys:
| Parameter | Common Key | Example Change |
|---|---|---|
| Width | w= or width= | Change 400 to 1200 for higher res. |
| Height | h= or height= | Change 300 to 600. |
| Quality | q= or quality= | Change 75 to 100 for less compression. |
| Crop | crop= | Often set to true, center, or face. |
Pro Tip: If you want the highest quality version possible, try removing the query parameters entirely (everything from the ? onwards). Sometimes the server will default to the original, uncompressed source file.
Would you like me to check if that specific CDN supports other parameters like quality or cropping?