Maximum file size with lightning:input/lightning-input type=file?

Question

I had answered this question more than a year back where the file size was clearly documented to be 1 MB unless chunked to increase the limit to 4 MB, while using lightning:input and type="file".

However revisiting this for an implementation in LWC (assuming the limits would have remained same), I cannot find that same information on the documentation available anymore! While testing it seems the limit now is actually close to the payload limit of < 4MB (the actual file size that can be passed to the backend to be uploaded).

Does anyone know if there was an update on the component or there is a documentation available which speaks about the actual size limits while using the input component in aura or lwc?

Answer 1

There is no limit on the file size, which is why there's no documentation on such a limit; the component uses an input to provide the file selecting functionality. Here's a quick example I wrote up for you:

<aura:application extends="force:slds">
    <aura:attribute name="selectedFileSize" type="Integer" default="0" />
    <lightning:input type="file" onchange="{!c.show}" label="File" />
    <lightning:formattedNumber value="{!v.selectedFileSize}" />
</aura:application>

---

({
    show: function(component, event, helper) {
        let fileReader = new FileReader();
        fileReader.onload = $A.getCallback(function() {
            component.set("v.selectedFileSize", fileReader.result.length);
        });
        fileReader.readAsBinaryString(event.getSource().get("v.files")[0]);
    }
})

With an example where I read a 194MB file into this binary string: