294.69 MB ── canvas-2d-pixels
   0.00 MB ── d3d11-shared-textures
   0.00 MB ── d3d9-shared-texture
   0.00 MB ── d3d9-shared-textures
   0.00 MB ── gfx-d2d-vram-draw-target
   0.00 MB ── gfx-d2d-vram-source-surface
  42.15 MB ── gfx-surface-win32
   0.00 MB ── gfx-textures
   0.00 MB ── gfx-tiles-waste
         0 ── ghost-windows
 200.44 MB ── heap-allocated
       532 ── heap-chunks
   1.00 MB ── heap-chunksize
 208.28 MB ── heap-committed
 532.00 MB ── heap-mapped
     3.91% ── heap-overhead-ratio
         0 ── host-object-urls
   1.56 MB ── imagelib-surface-cache-estimated-locked
   3.05 MB ── imagelib-surface-cache-estimated-total
         0 ── imagelib-surface-cache-overflow-count
   4.77 MB ── js-main-runtime-temporary-peak
         0 ── low-commit-space-events
 726.97 MB ── private
 408.57 MB ── resident
   3.79 MB ── system-heap-allocated

 120.34 MB ── vsize-max-contiguous

The longer I use FF the more memory it demands. I run very few active add-ons and plugins. Every plugin is "ask to activate" and only Flash is active at the moment. Add-ons (I only have 4): about:addons-memory Free Memory 2.0 LastPass Restartless Restart (used daily ;-) Somehow, with only a single tab open that has no content except the about:memory report, about:memory shows 300MB in canvas-2d-pixels. That is approaching one half of the private working set size. It seems excessive. 294.69 MB ── canvas-2d-pixels 0.00 MB ── d3d11-shared-textures 0.00 MB ── d3d9-shared-texture 0.00 MB ── d3d9-shared-textures 0.00 MB ── gfx-d2d-vram-draw-target 0.00 MB ── gfx-d2d-vram-source-surface 42.15 MB ── gfx-surface-win32 0.00 MB ── gfx-textures 0.00 MB ── gfx-tiles-waste 0 ── ghost-windows 200.44 MB ── heap-allocated 532 ── heap-chunks 1.00 MB ── heap-chunksize 208.28 MB ── heap-committed 532.00 MB ── heap-mapped 3.91% ── heap-overhead-ratio 0 ── host-object-urls 1.56 MB ── imagelib-surface-cache-estimated-locked 3.05 MB ── imagelib-surface-cache-estimated-total 0 ── imagelib-surface-cache-overflow-count 4.77 MB ── js-main-runtime-temporary-peak 0 ── low-commit-space-events 726.97 MB ── private 408.57 MB ── resident 3.79 MB ── system-heap-allocated 1,410.42 MB ── vsize 120.34 MB ── vsize-max-contiguous Before I waste more of my time, or any of yours, would you mind closing your tabs (at the end of the day for example) except for a single empty new tab, and letting me know how much memory your Firefox shows under about:memory canvas-2d-pixels (it's in the very last group of metrics) I would appreciate it! Thanks, David Update: Less than 24 hours later: 636.88 MB ── canvas-2d-pixels Update: Added images from VMMap and Process Explorer showing this firefox process and how memory use has changed over time