How do I send big files in nodejs from the client to the server without an "Uncaught out of memory" error?

When sending a big file, such as one over twenty megabytes from the client to the server using a fetch request, the HTML page with the file input freezes for about 10 seconds and gives the error in the console:

"Uncaught out of memory"

This is my JavaScript code that I think is part of the issue:

for (let i = 0; i < files.length; i++) {
const file = files[i];
const reader = new FileReader();

reader.onload = function(event) {
const fileData = new Uint8Array(event.target.result);

const postFileData = {
    file: {
        name: file.name,
        type: file.type,
        data: Array.from(fileData)
    }
}

fetch("/file", {
    method: "POST",
    headers: {
        "Content-Type": "application/json"
    },
    body: JSON.stringify(postFileData)
});
};

I tried making the code split the file's post data and send it one by one, however I am not sure how to properly do it.

Solution

You have to make smaller part of file and then upload.

for (let i = 0; i < files.length; i++) {
                const file = files[i];
                const chunkSize = 2 * 1024 * 1024; // 2MB per chunk
                const totalChunks = Math.ceil(file.size / chunkSize);

                for (let j = 0; j < totalChunks; j++) {
                    const start = j * chunkSize;
                    const end = Math.min(start + chunkSize, file.size);
                    const chunk = file.slice(start, end);
                    const formData = new FormData();
                    formData.append('chunk', chunk, file.name);
                    formData.append('chunkIndex', j);
                    formData.append('totalChunks', totalChunks);

                    fetch('/upload-chunk', {
                        method: 'POST',
                        body: formData
                    })
                    .then(response => response.json())
                    .then(data => {
                        if (data.success && j === totalChunks - 1) {
                            console.log('File uploaded successfully');
                        }
                    })
                    .catch(error => console.error('Error uploading chunk:', error));
                }
            }