Differences between Path Variables vs Query Parameters in API Testing on Postman
Both path variables and query parameters are ways to dynamically send data to an API when making a request, but they serve different purposes. Here’s a breakdown of their key differences:
Path Variables
Inserted directly into the URL path itself, replacing specific segments enclosed in curly braces ({}). Major purpose is Identify specific resources within the API.
/users/{id} where {id} would be replaced with a specific user ID. It changes the fundamental structure of the URL, indicating a different resource.
Modification in Postman:
- Entered directly in the URL path.
- Can be saved as a collection variable for reuse.
Query Parameters
Appended to the URL after a question mark (?) as name-value pairs separated by ampersands (&). Provide additional information or filter criteria to the API call.
/users?page=2&limit=10 to retrieve users on page 2 with a maximum of 10 results. It appended information without changing the core resource being accessed.
Modification in Postman:
- Entered in the “Params” tab as key-value pairs.
- Can be saved as collection variables or environment variables for reuse.
Key Differences
Additional Takeaways
- Path variables are mandatory and must be provided for the API to identify the resource.
- Query parameters are optional and can be omitted if not needed.
- The number of path variables is typically limited, while query parameters can be numerous.
- Path variables often represent unique identifiers, while query parameters provide more flexible data.
How to choose the right method?
The choice between path variables and query parameters depends on the specific API design and your needs. Use path variables when you need to identify a specific resource within the API and Use query parameters when you need to provide additional information or filter criteria without changing the core resource being accessed.
