How to Use Variables in URL in Postman for Dynamic Requests

In Postman, you can use variables in the URL by enclosing the variable name in double curly braces like {{variableName}}. Define these variables in environments or globals, and Postman will replace them with their values when sending the request.

Syntax

Use variables in Postman URLs by wrapping the variable name with double curly braces {{variableName}}. This tells Postman to replace it with the variable's value from the selected environment or global variables.

For example, https://api.example.com/users/{{userId}} uses the variable userId in the URL.

text

https://api.example.com/resource/{{variableName}}

Example

This example shows how to use an environment variable userId in the URL to get user details dynamically.

First, define userId in your environment with a value like 123. Then use the URL with the variable.

http

GET https://api.example.com/users/{{userId}}

Output

Request sent to https://api.example.com/users/123 with userId replaced by 123

Common Pitfalls

• Not defining the variable in the selected environment or globals causes Postman to send the URL with the variable name unchanged, leading to errors.
• Using incorrect variable names or typos inside {{}} will not resolve the variable.
• Forgetting to select the correct environment where the variable is defined will cause unresolved variables.

Always check your environment variables and spelling.

http

GET https://api.example.com/users/{{userid}}

// Wrong: variable name is case-sensitive and should be 'userId'

// Correct:
GET https://api.example.com/users/{{userId}}

Quick Reference

Concept	Usage	Notes
Variable syntax	{{variableName}}	Wrap variable name in double curly braces
Define variable	In Environment or Globals	Set variable value before use
Select environment	Choose environment in Postman UI	Active environment provides variable values
Variable case	Case-sensitive	Match variable name exactly
Fallback	Use globals if not in environment	Globals are shared across environments

Key Takeaways

Use double curly braces {{variableName}} to insert variables in Postman URLs.

Always define variables in the active environment or global variables before using them.

Variable names are case-sensitive; ensure exact spelling inside {{}}.

Select the correct environment in Postman to resolve variables properly.

Unresolved variables in URLs cause request errors or incorrect endpoints.