DEV Community: Veljko

PUT vs PATCH

Veljko — Thu, 24 Apr 2025 14:43:57 +0000

PUT and PATCH are HTTP methods used to update a resource. They are both for updating a resource, yet they differ in how they apply updates.

PUT

PUT replaces the entire resource with new values, it overwrites all fields.

Behavior:

If the resource exists, it is completely replaced with the new version, it getts overwritten.
If a field is missing in the request, it gets removed.

Example

Imagine you have a user resource with this initial data:

{
  "id": 123,
  "firstName": "John",
  "lastName": "Doe",
  "age": 25,
  "email": "john@doe.com"
}

And I want to change the age and email. So, we send the following PUT request:

{
  "age": 20,
  "email": "john.new@doe.com"
}

The updated resource will now be:

{
  "age": 20,
  "email": "john.new@doe.com"
}

The id, firstName and lastName fields got deleted. Since in our PUT request we included only age and email fields (since those are the only ones we need to update), those got overwritten with new values, while the missing ones got removed.

PATCH

PATCH method updates only the specified fields of a resource without touching the others.

Behavior:

Only the provided fields are updated.
Missing fields remain unchanged.

As opposed to PUT method, this one doesn't remove the missing fields, just updates the specified ones, whereas PUT overwrites the specified and removes missing ones.

Example

Let's take the same example as before, intial data:

{
  "id": 123,
  "firstName": "John",
  "lastName": "Doe",
  "age": 25,
  "email": "john@doe.com"
}

The same request, only this time we're using PATCH method:

{
  "age": 20,
  "email": "john.new@doe.com"
}

The result is:

{
  "id": 123,
  "firstName": "John",
  "lastName": "Doe",
  "age": 20,
  "email": "john.new@doe.com"
}

PATCH method updated the specified fields with new values without touching other fields that weren't specified in the request, whereas PUT would've deleted those.

PATCH vs PUT

When updating data via an API, should you use PUT or PATCH? While both modify resources, they work differently.

PUT replaces the entire resource, removing unspecified fields
PATCH updates only specific fields, leaving the rest untouched

If using PUT, you're forced to send a request with full resource, otherwise unused ones will be removed.
PATCH is usually safer since it won’t accidentally remove existing fields.

When to use which?

PUT:

Updating an entire object: If you're sending a complete update (e.g., replacing an entire profile).
Replacing an existing resource: If you expect the resource to be fully refreshed.
Ensuring consistency: If you want a predictable, clean state.

PATCH:

Making minor changes: If you only need to update one or a few fields.
Preserving existing data: When you don’t want to overwrite fields unnecessarily.
Reducing bandwidth usage: If you want a more efficient request.

Summary

Feature	PUT	PATCH
Update Type	Full replacement	Partial update
Fields required?	Yes, all fields must be sent	No, only changed fields are sent
If a field is missing?	It gets removed	It stays unchanged
Data Size	Larger (sends full resource)	Smaller (sends only changes)
Best Use Case	When you want to replace the entire resource	When you only need to update specific fields

^ (Caret) and ~ (Tilde) in package.json

Veljko — Thu, 06 Mar 2025 12:09:59 +0000

You must have seen at least once package.json file throughout your developer journey.
package.json is a file that contains information about a project, among which are project dependencies and their corresponding versions.
But then, you must have noticed that some versions have ^ (caret) or ~ (tilde) in front of them. What are they for and what do they mean?

REMINDER: x.x.x format

Example:

"pg": "8.7.3"

The x.x.x format you see in version numbers follows this structure:

MAJOR.MINOR.PATCH

So, in the example above:

8 - MAJOR
7 - MINOR
3 - PATCH

`~` (Tilde) - Patch Updates

Allows only patch updates within the same minor version.

"mongoose": "~6.2.2"

Allows updates up to 6.2.x, but not 6.3.0.
Here, it will install new versions like 6.2.3, 6.2.7, 6.2.9, but it will not install 6.3.0.

Why use `~`?

For backend libraries, especially security-related ones, developers often want to allow only patch updates to avoid breaking API changes.

`^` (Caret) - Minor and Patch Updates

Allows updates only within the same major version, meaning it allows only minor and patch updates.

"react": "^18.2.0"

Allows 18.2.0 up to 18.x.x, but not 19.0.0.
Here it will install new versions like 18.2.3, 18.3.4, 18.5.2, 18.8.6, but it will not install 19.0.0.

Why use `^`?

Frontend libraries frequently release minor updates, so ^ helps get the latest bug fixes and performance improvements without breaking the major version.

Summary

Symbol	Example	Allowed Updates
`^`	`^4.17.21`	`4.17.21` → `4.x.x` (not `5.0.0`)
`~`	`~4.17.1`	`4.17.1` → `4.17.x` (not `4.18.0`)

DEV Community: Veljko

PUT vs PATCH

PUT

Example

PATCH

Example

PATCH vs PUT

When to use which?

Summary

^ (Caret) and ~ (Tilde) in package.json

REMINDER: x.x.x format

~ (Tilde) - Patch Updates

Why use ~?

^ (Caret) - Minor and Patch Updates

Why use ^?

Summary

`~` (Tilde) - Patch Updates

Why use `~`?

`^` (Caret) - Minor and Patch Updates

Why use `^`?