Firefox 156, first released on September 15, includes faster startup for its built-in PDF viewer and changes intended to reduce memory and CPU use when displaying large JPEG images scaled down on a page.
Mozilla’s release notes also list platform-specific additions and fixes affecting picture-in-picture subtitles, split view, bookmarks and network connectivity.
PDFs and images receive performance work
Mozilla says the PDF viewer starts up to 45% faster. That is the developer’s stated improvement, not an independent result for every document or device. Startup time and the performance of reading or searching a large document are different measurements.
The official release notes also report improved resource use for large JPEGs shown at smaller sizes. The change concerns browser handling; publishers still benefit from serving appropriately sized images instead of relying on the browser to shrink unnecessarily large files.
On Windows ARM64 devices, WebRTC calls may now use hardware H.264 decoding where supported instead of software decoding. Its effect depends on the device and call configuration.
Suggestions expand in three countries
Localized Wikipedia suggestions and occasional sponsored suggestions in the address bar are now available in France, Germany and Italy. Mozilla says users can turn them off in Firefox Suggest settings.
On macOS, the browser adds an option in Startup settings to open Firefox automatically when the computer starts. Users who do not want that behavior should check the setting rather than treating it as a requirement of the update.
Fixes address specific browsing failures
The release includes fixes for subtitles enabled after a picture-in-picture window opens, the find bar becoming unavailable after reversing split-view panes and some connectivity problems involving the built-in VPN or DNS over HTTPS.
Mozilla also lists security fixes. Users should obtain updates through the browser’s normal update mechanism or the official distribution for their system, including applicable enterprise policies.
Browser updates and extension access solve different problems. After updating, it remains useful to review what installed extensions can read, particularly tools that request access to all websites.
