Can you paste here URL to that file? For me, PDF rendering is quite fast; sometimes it's even better than Adobe Reader.

Does it still happen in Troubleshoot Mode?

Can you paste here URL to that file? For me, PDF rendering is quite fast; sometimes it's even better than Adobe Reader.

@TyDraniu here is the PDF link https://drive.google.com/file/d/14gXDqBf2tf1rdHr-ggQAKapXAIpSvEAr/view?usp=drive_link

The same file when opened in Edge the page loading is smooth. I have tried with bigger PDF files. Edge handles them well but when I open it in Firefox it just takes ages to load.

@zeroknight Yes, just checked the issue persists in Troubleshoot Mode.

I can't access it.

I can't access it.

Sorry, I forgot to make it public, now you can access it.

It looks like it's due to weight of the file. It has 100 MB for 2 pages. I don't think we can do anything about improving the situation at this moment.

It looks like it's due to weight of the file. It has 100 MB for 2 pages. I don't think we can do anything about improving the situation at this moment.

But this same file opens normally in edge. I'm sharing another file of around 6mb. This file also takes ages to load in Firefox https://drive.google.com/file/d/1sbQdmfhHGOVb5l2ja_NwcVkx8D1Fwenn/view?usp=drive_link Please check

I reported that to developers. Please follow https://github.com/mozilla/pdf.js/issues/18002

Thanks for the help.

Firefox has been my default browser for more than 10 years. Now to open PDF if I have to use EDGE that's bad. Hope, this gets fixed.

The 2nd file takes less than 2 seconds to open for me. see screenshot What security software are you running? Have you tried the same steps under a different user profile? If you're running Windows Pro version, I would test in the Sandbox to confirm. https://www.howtogeek.com/399290/how-to-use-windows-10s-new-sandbox-to-safely-test-apps/

The 2nd file takes less than 2 seconds to open for me. see screenshot What security software are you running? Have you tried the same steps under a different user profile? If you're running Windows Pro version, I would test in the Sandbox to confirm. https://www.howtogeek.com/399290/how-to-use-windows-10s-new-sandbox-to-safely-test-apps/

Are you using a Linux system? How did you add the option to see the load time? I am using Windows Defender. Even in Troubleshoot mode, nothing changes. I have tried private mode, which took around 25 sec to load and the same in normal mode. I am running Windows 11 Pro and will test in sandbox mode. I think Edge renders faster than Firefox as Edge renders section by section when scrolling while Firefox loads the whole PDF at once.

I'm sharing another file of around 6mb.

Where are you getting these slow PDFs from? Do you know what software is being used to generate them?

The 2nd file takes less than 2 seconds to open for me. see screenshot

You need to save the file and open it with the built-in PDF viewer.

Where are you getting these slow PDFs from? Do you know what software is being used to generate them?

These are Website design Templates created using Figma.

You need to save the file and open it with the built-in PDF viewer.

The File is already there in my system. I am not opening the file from Online.

Seems my previous comment is waiting for mod approval.

I saved the file and it took about 3-5 seconds to open. If it's taking a long time to open from a saved location, you should provide info about your system. Post a screenshot of the performance tab. Edge rendering faster is not a surprise because it's using the same engine as Chrome, but I'm more curious about the system.

Here is my sys info. Let me go try on Windows.

Operating System: openSUSE Leap 15.6 KDE Plasma Version: 5.27.11 KDE Frameworks Version: 5.115.0 Qt Version: 5.15.12 Kernel Version: 6.4.0-150600.13-default (64-bit) Graphics Platform: X11 Processors: 16 × AMD Ryzen 7 PRO 6850HS with Radeon Graphics Memory: 62.1 GiB of RAM Graphics Processor: AMD Radeon Graphics Manufacturer: HP Product Name: HP EliteBook 865 16 inch G9 Notebook PC

On Windows it took a wee bit longer, around 10 seconds to open. My sys info.

Device name ZBook-17-G7 Processor Intel(R) Xeon(R) W-10885M CPU @ 2.40GHz 2.40 GHz Installed RAM 128 GB (127 GB usable) System type 64-bit operating system, x64-based processor Pen and touch No pen or touch input is available for this display

Edition Windows 11 Pro for Workstations Version 24H2 Installed on ‎20-‎Apr-‎24 OS build 26100.1 Experience Windows Feature Experience Pack 1000.26100.1.0

On Windows it took a wee bit longer, around 10 seconds to open. My sys info.

With the specs your system has and still it takes 10 sec then I don't expect mine to load any faster. My system specs: Device name Avisek_lappy Processor Intel(R) Core(TM) i7-3610QM CPU @ 2.30GHz 2.30 GHz Installed RAM 8.00 GB (7.89 GB usable) System type 64-bit operating system, x64-based processor Pen and touch No pen or touch input is available for this display Edition Windows 11 Pro Version 23H2 Installed on ‎06-‎12-‎2023 OS build 22631.3527 Experience Windows Feature Experience Pack 1000.22700.1003.0

Here is the data from the performance tab: https://share.firefox.dev/3JB832E

I don't know how did you took that performance Screenshot. I have shared the web-developer performance tab data.

I found reddit post regarding the same. https://www.reddit.com/r/firefox/comments/197o8l7/anyone_notice_that_firefox_windows_renders_pdfs/

I forgot to test in Edge because it's not part of my thought process, but anyway Edge is clearly faster when opening the PDF from my desktop. With your computer specs, I see why it takes even longer for you.

I would like to know why are you using Firefox to open the PDF when Adobe is much faster. Acrobat opens the same file in about 2 seconds on my computer. What type of hard drive are running? I would guess an old 2.5 Sata SSD. I'm on a M.2 ssd WD_BLACK SN770 1TB. I would suggest visiting eBay. Just looked and you can get something less than a year old, with HP warranty and ebay guarantee. This is just an example (not associated with it, just a HP laptop fan) of what you can get with a little research. HP ProBook 455 15.6" G10 FHD Laptop Ryzen 7 AMD Radeon 16GB DDR4 RAM 512GB SSD

Currently have the G9 and it holds 2 drives, I run laptops that hold more than 1 drive, but it's just a long time preference of mine.  ;-) If you want better performance, it's time to upgrade.

Here are the specs from Intel on your processor. https://ark.intel.com/content/www/us/en/ark/products/64899/intel-core-i7-3610qm-processor-6m-cache-up-to-3-30-ghz.html Looks like your computer is around 12yrs old. I have a HP ZBook 17 G2 with a 4th generation processor running Windows 7. I'm sure your computer barely meets Microsoft's specs to even run Windows 11.

I would also suggest upgrading your current laptop with M.2 drives and maxing out the ram for better performance. You can visit the link below to get an idea of how much ram your computer can hold.

https://www.crucial.com/store/systemscanner

Looking at the specs for your processor from Intel, it appears that your max ram is 32GB.

I know my system is old but it runs normal tasks well. If your Windows system having 128 GB RAM takes 10 sec to load a 5 MB PDF in Firefox then it won't do much good for me. Even if I put 32 GB RAM in my system. The problem here is not my system, else Edge would also be slow but the way Firefox renders PDF files. That is why it takes a long time to load. I will use EDGE to view PDF for the time being.

Anyways thanks for the help.

This file also takes ages to load in Firefox https://drive.google.com/file/d/1sbQdmfhHGOVb5l2ja_NwcVkx8D1Fwenn/view?usp=drive_link

That file takes about 19 seconds to render for me (two-year-old Windows).

The built-in PDF viewer (and Acrobat Document properties) show:

Page Size: 17.78 × 84.22 in (portrait)

It wouldn't surprise me if the page size is a challenge due to limitations on bitmap image dimensions.

The 2nd file takes less than 2 seconds to open for me. see screenshot

The Google Drive previewer overlay is wicked fast compared with rendering the PDF in its own tab. I'm not sure why there is such a big difference. There is a note in the corner "Comments were not imported due to a problem within the file," but that seems rather minor, unless "problem within the file" is an important clue.

Maybe it's a quick-and-dirty workaround to load slow PDFs into Google Drive and read them in their previewer?

I reported that to developers. Please follow https://github.com/mozilla/pdf.js/issues/18002

Thanks. Hopefully more examples can be added to that issue (or maybe there are related issues with other examples) so commonalities can be discovered.