Can we use query parameters instead of the request body?

Yes, but it depends on the type of request and the transmitted information.

Query Parameters

• Passed in the URL after the ? sign as key=value pairs, separated by &.
• Often used for GET requests to filter, sort, paginate data (e.g., /api/items?category=electronics&sort=price).
• Limited in size in most browsers and servers.
• Visible in server logs and browser history (potential security issue for sensitive data).
• Easily cached.

Request Body

• Sent in the body of the HTTP request.
• Often used for POST, PUT, PATCH requests to transmit large amounts of data, create or update resources (e.g., form submission, JSON object).
• No strict size limitations (within server configurations).
• Not visible in the URL, making it more suitable for transmitting sensitive data.
• Not cached by browsers by default.
• Can contain various data types (JSON, XML, forms).

Summary of differences:

Criterion	Query Parameters	Request Body
Placement	URL (after ?)	HTTP request body
Typical methods	GET	POST, PUT, PATCH
Usage	Filtering, sorting, pagination	Creating/updating resources, transmitting large data
Size	Limited	Virtually unlimited
Visibility	Visible in URL	Not visible in URL
Caching	Easily cached	Not cached (by default)
Security	Less suitable for sensitive data	More suitable for sensitive data

When to use one instead of the other:

• Query Parameters instead of Body: theoretically possible for POST, PUT, etc., but not recommended for transmitting the main payload of the request. It can violate HTTP method semantics and complicate processing. Rarely used, mainly for very simple cases or specific architectures. Transmitting large or structured data via query string is impractical.
• Body instead of Query Parameters: impossible for GET requests, as the HTTP standard does not define semantics for the request body in GET. For other methods (POST, PUT, etc.), the request body is the standard way to transmit data and is preferable when transmitting structured or large volumes of information, or when data is sensitive.

In most cases, it is advisable to follow common conventions: use query parameters for GET requests for filtering/identification and body for sending data in state-changing requests (POST, PUT, PATCH).