Understanding the Differences Between HTTP GET and POST Methods

GET and POST are the two basic HTTP request methods, differing primarily in how they transmit parameters.

GET includes parameters in the URL, while POST sends them in the request body.

Common interview answers highlight differences such as bookmarking, caching, length limits, encoding, visibility in history, and security.

GET is harmless on browser back navigation; POST may resubmit.

GET URLs can be bookmarked; POST cannot.

GET responses are cached by browsers; POST is not unless configured.

GET uses URL‑encoding only; POST supports multiple encodings.

GET parameters appear in browser history; POST parameters do not.

GET URLs have length limits (≈2 KB in browsers, ≈64 KB on servers); POST does not.

GET accepts only ASCII characters; POST has no such restriction.

GET exposes parameters in the URL, making it less suitable for sensitive data.

Both methods ultimately use TCP connections.

Although the “standard answer” lists many differences, the underlying protocol (TCP) treats GET and POST similarly; the distinction lies in HTTP specifications and practical limits imposed by browsers and servers.

GET and POST are both TCP‑based; you can technically send a request body with GET or URL parameters with POST, but such usage is unconventional.

Browser and server implementations impose practical limits: most browsers restrict URL length to about 2 KB, and many servers cap URLs at around 64 KB, which explains the size‑related differences often cited.

In practice, GET typically results in a single TCP packet exchange (header and data together), whereas POST often involves a two‑step exchange (header, 100‑Continue response, then data), leading to slightly higher latency.

Nevertheless, both methods have distinct semantics and should not be interchanged arbitrarily; network conditions, browser behavior, and server configurations can affect performance and reliability.

Overall, while GET and POST are fundamentally the same TCP connection, HTTP rules and implementation constraints give them observable differences in real‑world usage.