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I get the following error:

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/C:/Users/Vash/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/C:/Users/Vash/.m2/repository/org/slf4j/slf4j-jdk14/1.7.25/slf4j-jdk14-1.7.25.jar!/org/slf4j /impl/StaticLoggerBinder.class]

I've already checked https://www.slf4j.org/codes.html#multiple_bindings
and similar questions. I've found using mvn dependency:tree that 4 dependencies use SLF4J so I've added the exclusion to them like this:

<dependency>
<groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-web</artifactId>
 <exclusions>
 <exclusion>
 <groupId>org.slf4j</groupId>
 <artifactId>slf4j-log4j12</artifactId>
 </exclusion>
 <exclusion>
 <groupId>log4j</groupId>
 <artifactId>log4j</artifactId>
 </exclusion>
</exclusions>

This didn't change anything and I still get the same error. I've tried deleting the .jar files specified in the warning but then I get error about missing classes. Also I'm using IntelliJ so maybe somehow reloading the pom.xml file is the issue here?

I think this is a bug/feature in Maven. Let's assume you have this dependency tree:

A
+---B
 +---C
 | +---D
 |
 +---D

and you exclude D on B, it will still be there because C also pulls it in. From Maven's point of view this makes sense because it doesn't try to understand whether there is a relationship between B and C. We know that they're all from Spring but Maven can't be so sure.

Solution: You need to duplicate the exclusion on C in your POM.

Use mvn dependency:tree to find all places where D is being used and add one exclusion each.

And make sure you actually exclude D. In your example above, you exclude org.slf4j:slf4j-log4j12 instead of org.slf4j:slf4j-jdk14