Default FullZoom Level is a Firefox extension that offers toolbar buttons for Page zoom and Text zoom.

1.This extension can change Default FullZoom Level.
This extension is useful in the case of a high-definition display.

2.Manual/Automatic Fit To Window Full Zoom.

3. The zoom mode is restored every domain name or tab as well as the zoom level.

4. In the case of a local file, you can set whether zoom every file or every folder.

5. Two toolbar buttons are provided.
"A":Text Zoom BUtton.
"P":Full Zoom Button.
Left, middle, right button click will enlarge, reset and reduce page or text respectively.
Wheel button rotation will enlarge and reduce them.
And Shift+right click show up the option dialog.

6.Indicate Zoom level in Statusbar.
Left click : popup zoom level list
Middle click: reset zoom level
Right click: toggle zoom mode.

7. Keyboard shortcut:
TextZoom reduce :accel+ , (comma)
TextZoom reset :accel+ . (dot)
TextZoom enlarge :accel+/
Fullzoom reduce : default(accel+-)
Fullzoom reset : default(accel+0)
Fullzoom enlarge : default(accel++)
Fullzoom Fit to window: accel+shift+?
Where, An accel key may be a crtl key in Windows's keyboard.

Requirements:

Ссылка: https://addons...efox/downloads/file/134648/default_fullzoom_level-4.6.1-fx.xpi