I decided to create one more validation, this time in user side (java-script).

I would like to do it in simple way. I decided to convert inputs files to the array, and then remove file.

my code

    let uploadField = document.getElementById("file"); //mój input

       uploadField.addEventListener('change', checkFileSize)

    
      
       function checkFileSize() {

           let amount_files = uploadField.files.length;
           
           let files_array = Array.from(uploadField.files);
       

           let maxsize = 3*1024*1024;

           console.log(Array.isArray(files_array));
          
           for(let i = 0; i < amount_files; i++) {

              if(files_array[i] >  maxsize) {
               files_array.splice(i, 1);
               
               
              }
              
           }
           console.log(files_array);
       }    

I think that on this line

if(files_array[i] > maxsize

I should put file size after "if" , but I don't know how to get it (i saw this property on console)