SUMMARY STEPS TO REPRODUCE 1. Download https://methowtrails.org/assets/wintertrails_winthroptobrownsfarm_2026.pdf (I am not attaching it to this ticket because it's larger than the bug platform upload limit) 2. Open this PDF in Okular OBSERVED RESULT It takes about 1 minute 3 seconds on my machine to render this PDF. When I open the same PDF (from the local filesystem) in Firefox, it takes 7 seconds. When I open the same PDF on my iPhone 12 Pro, it likewise takes less than 10 seconds. EXPECTED RESULT Okular should take about as long as Firefox does to render the PDF. SOFTWARE/OS VERSIONS Operating System: NixOS 26.05 KDE Plasma Version: 6.5.4 KDE Frameworks Version: 6.20.0 Qt Version: 6.10.1 Kernel Version: 6.18.0 (64-bit) Graphics Platform: Wayland Processors: 22 × Intel® Core™ Ultra 7 155H Memory: 32 GiB of RAM (31.0 GiB usable) Graphics Processor: Intel® Arc RELATED ISSUES Very slow render time on restaurant menu https://bugs.kde.org/show_bug.cgi?id=464716 The app inmediatelly crashes when trying to open a long pdf https://bugs.kde.org/show_bug.cgi?id=494388 PDF Rendering issues: Takes many seconds to render new page and renderings are not cleared on zooming https://bugs.kde.org/show_bug.cgi?id=469886