Setting chunk size by URL options

[T0mazz]

Is there a way to configure chunk size by using the official pdf.js viewer (params after the ? or # in the URL) and without changing the source code ?

If not, is it planned to implement this functionality in a future pdf.js version ?

[Snuffleupagus]

First of all, as mentioned in multiple places the default viewer isn't intended to be used as-is without modification; see e.g. https://mozilla.github.io/pdf.js/getting_started/#introduction and https://github.com/mozilla/pdf.js/wiki/Setup-pdf.js-in-a-website#from-examples

Is there a way to configure chunk size by using the official pdf.js viewer (params after the ? or # in the URL) and without changing the source code ?

However there's a work-around available, as is explained in the FAQ; see https://github.com/mozilla/pdf.js/wiki/Frequently-Asked-Questions#file. Hence it's possible to load the viewer without opening a PDF file, e.g. try https://mozilla.github.io/pdf.js/web/viewer.html?file= and then calling PDFViewerApplication.open(file, { rangeChunkSize: /* custom value here */, }); afterwards; please refer to the docs:

pdf.js/web/app.js

Lines 692 to 701 in 76337fd

	/**
	* Opens PDF document specified by URL or array with additional arguments.
	* @param {string|TypedArray|ArrayBuffer} file - PDF location or binary data.
	* @param {Object} args - (optional) Additional arguments for the getDocument
	* call, e.g. HTTP headers ('httpHeaders') or
	* alternative data transport ('range').
	* @returns {Promise} - Returns the promise, which is resolved when document
	* is opened.
	*/
	open(file, args) {

If not, is it planned to implement this functionality in a future pdf.js version ?

Allowing hash parameters to control various API options in this way has the potential to be a huge performance footgun, which is why it's purposely disabled in PR #4956. (The fact that it ever worked was a bug, and not a feature.)
Hence that's not something that should be implemented, besides as explained above a work-around is already available (if you don't want to change the code).