Difference Between PUT & PATCH Request

Difference Between PUT and PATCH Request

In the world of web development and RESTful APIs, understanding the nuances between different HTTP methods is essential for designing efficient and effective communication between clients and servers. Two commonly used HTTP methods for updating resources are PUT and PATCH. While both are used to modify existing resources, they operate in distinct ways and are suited for different scenarios. In this guide, we will explore the key differences between PUT and PATCH requests, their use cases, and best practices for using each method.

Introduction to HTTP Methods

HTTP methods define the actions that can be performed on resources in a web application. Common HTTP methods include GET, POST, PUT, DELETE, and PATCH. Among these, PUT and PATCH are specifically used for updating existing resources:

PUT: The PUT method is used to update or replace an existing resource with the data provided in the request body. If the resource does not exist, PUT can also create a new resource.

PATCH: The PATCH method is used to apply partial modifications to an existing resource. Unlike PUT, PATCH only updates the specified fields without altering the entire resource.

Key Differences Between PUT and PATCH

Although both PUT and PATCH are used to update resources, they differ significantly in how they handle updates:

Scope of Update

• PUT: Replaces the entire resource with the new data provided in the request. This means that all attributes of the resource are updated, even if only some values are changed. If any attribute is not included in the PUT request, it will be removed from the resource.
• PATCH: Updates only the specified fields in the resource. It makes minimal changes, altering only the fields that are included in the request body, leaving the rest of the resource unchanged.

Idempotency

• PUT: PUT requests are idempotent, meaning that making the same request multiple times will result in the same outcome. For example, if you send a PUT request to update a user’s profile with the same data multiple times, the profile will remain the same after the first request.
• PATCH: PATCH requests are also idempotent, but only if applied correctly. A PATCH request with the same modifications can be repeated without changing the outcome, as long as the patch does not include operations that are inherently non-idempotent, like incrementing a value.

Request Body

• PUT: The request body of a PUT request contains the complete representation of the resource. This includes all fields, even if only some are being updated. The server replaces the current resource with the new representation provided by the client.
• PATCH: The request body of a PATCH request contains only the fields that need to be updated. This can be as minimal as a single field, making PATCH more efficient when dealing with partial updates.

Use Case Scenarios

• PUT: Use PUT when you want to completely replace an existing resource or create a new resource at a specific URL. It’s ideal for cases where the full state of the resource is known and needs to be updated.
• PATCH: Use PATCH when you need to make partial updates to a resource without sending the entire data set. PATCH is useful for scenarios where only specific fields need to be modified, such as updating a user’s email address without changing other profile information.

Performance and Efficiency

• PUT: Since PUT requires the complete resource representation, it can be less efficient when only small changes are needed. This can lead to increased network traffic and processing time, especially for large resources.
• PATCH: PATCH is more efficient for partial updates because it only transmits the changes. This reduces the payload size and improves performance, making it suitable for applications where bandwidth and processing efficiency are critical.

Practical Examples

To better understand the differences between PUT and PATCH, consider the following scenarios:

Updating a User Profile with PUT: If you use PUT to update a user profile, you must send the entire profile, including all fields like name, email, and address. Even if only the email has changed, the entire profile needs to be included in the PUT request, and the server will replace the existing profile with this new data.

Updating a User Profile with PATCH: If you use PATCH to update the same user profile, you can send just the modified fields. For example, if only the email address has changed, the PATCH request can include just the new email, and the server will update only that field, leaving the rest of the profile unchanged.

When to Use PUT vs. PATCH

Use PUT When:

• You need to completely replace a resource.
• The entire resource state is known and must be updated.
• Creating or replacing a resource at a specific URL is required.

Use PATCH When:

• Only specific fields of a resource need to be updated.
• You want to minimize data transfer by sending only the changes.
• Partial updates are more efficient and suitable for your application needs.

Idempotency Considerations

Both PUT and PATCH are idempotent, meaning repeated identical requests should have the same effect as a single request. However, care must be taken with PATCH to ensure that the partial updates are indeed idempotent. For example, incrementing a counter using PATCH is not idempotent, as repeated requests would continually increase the counter, leading to unintended outcomes.

Performance Implications

Network Load: PUT requests can increase network load due to larger payloads, as they require sending the entire resource. This can be particularly impactful when dealing with large data sets or when network bandwidth is a concern.

Server Processing: PUT can also increase server processing as the server needs to handle the complete resource replacement. PATCH, being lighter, often results in less server load and quicker updates.

Best Practices

Choose Based on Need: Always choose between PUT and PATCH based on whether a full replacement or a partial update is required. Align the method with the action needed to maintain clear, predictable API behavior.

Maintain Consistency: Ensure consistent use of PUT and PATCH within your API to avoid confusion. Define clear guidelines and document when each method should be used.

Test for Idempotency: Especially when using PATCH, test your requests to ensure they are idempotent and handle repeated requests gracefully without causing unintended side effects.

Conclusion

Understanding the differences between PUT and PATCH is crucial for designing RESTful APIs that are efficient, clear, and maintainable. PUT is ideal for full replacements of resources, while PATCH excels in scenarios requiring partial updates. By carefully choosing the right method for your needs, you can optimize your API’s performance, reduce unnecessary data transfer, and provide a better experience for your users.

For a comprehensive guide and further examples, check out the full article: https://www.geeksforgeeks.org/difference-between-put-and-patch-request/.