Fit window to image

`↑ Shift` + `O`

All hotkeys for IrfanView

Browsing between images Go to next image in current directory	`Space`
Browsing between images Go to previous image in current directory	`⬅ Backspace`
View and zoom Scroll to the top of an image (when zoomed)	`Page Up`
View and zoom Scroll to the bottom of an image (when zoomed)	`Page Down`
Browsing between images Go to previous / next image in current directory	`← →`
Browsing between images ... to <keybs>9</keybs>: Move forward 1 - 9 images in current directory	`Ctrl` + `1`
Browsing between images ... to <keybs>9</keybs>: Move backward 1 - 9 images in current directory	`Ctrl` + `↑ Shift` + `1`
Browsing between images Load first image in current directory	`Ctrl` + `Home`
Browsing between images Load last image in current directory	`Ctrl` + `End`
Browsing between images Tag image	`X`
Browsing between images Untag image	`↑ Shift` + `X`
Browsing between images Show tagged files in the Thumbnails window	`↑ Shift` + `Q`
Handling files Rename file	`F2`
Handling files Rename file	`F6`
Handling files Batch convert or rename	`B`
Handling files Open	`O`
Handling files Properties	`P`
Handling files Save as	`S`
Handling files Open image in external viewer/editor	`↑ Shift` + `E`
Handling files Open random image from current directory	`Ctrl` + `M`
Handling files Open current image in new window	`Ctrl` + `N`
Handling files Print	`Ctrl` + `P`
Handling files Delete (Not: this command removes the file from the program's display, it doesn't delete the file)	`D`
Handling files Save dialog	`Ctrl` + `S`
Handling files Reopen	`↑ Shift` + `R`
Handling files Direct print image (no dialog box)	`Ctrl` + `Alt` + `P`
Handling files New image	`↑ Shift` + `N`
Full screen mode Toggle fullscreen mode	`⤶ Enter`
Full screen mode Loop through full screen image fit options	`F`
View and zoom Refresh view	`F5`
View and zoom Original size (reset zoom)	`Ctrl` + `H`
View and zoom Fit image to window	`↑ Shift` + `W`
View and zoom Zoom in	`+`
View and zoom Zoom in	`=`
View and zoom Zoom out	`-`
View and zoom Scroll image (when zoomed)	`← ↑ → ↓`
View and zoom Scroll to the left edge of an image (when zoomed)	`Home`
View and zoom Scroll to the right edge of an image (when zoomed)	`End`
View and zoom Fit only big images to desktop	`↑ Shift` + `F`
Full screen mode Lock/unlock zoom factor (applies current zoom to all loaded images)	`↑ Shift` + `L`
View and zoom Fit window to image	`↑ Shift` + `O`
View and zoom Toggle stretching image across all monitors	`Ctrl` + `↑ Shift` + `W`
Basic editing functions Horizontal flip	`H`
Basic editing functions Vertical flip	`V`
Basic editing functions Image information	`I`
Basic editing functions Rotate 90 degrees left	`L`
Basic editing functions Rotate 90 degrees right	`R`
Basic editing functions Custom rotation dialog	`Ctrl` + `U`
Basic editing functions Enhance colors	`↑ Shift` + `G`
Basic editing functions Sharpen	`↑ Shift` + `S`
Basic editing functions Auto color correction	`↑ Shift` + `U`
Basic editing functions Red eye reduction (on selected area)	`↑ Shift` + `Y`
Copy, paste and select Delete image	`Del`
Copy, paste and select Paste image	`Insert`
Copy, paste and select Move file	`F7`
Copy, paste and select Copy file	`F8`
Copy, paste and select Move the selection rectangle	`↑ Shift` + `← ↑ → ↓`
Copy, paste and select Select/unselect all	`Ctrl` + `A`
Copy, paste and select Copy	`Ctrl` + `C`
Copy, paste and select Paste	`Ctrl` + `V`
Copy, paste and select Copy current image name	`↑ Shift` + `P`
Copy, paste and select Cut	`Ctrl` + `X`
Copy, paste and select Crop image to selection	`Ctrl` + `Y`
Copy, paste and select Undo	`Ctrl` + `Z`
Copy, paste and select Auto crop image borders	`Ctrl` + `↑ Shift` + `Y`
Copy, paste and select Create custom selection	`↑ Shift` + `C`
Full screen mode Exit fullscreen mode	`Esc`
Main window Help	`F1`
Main window About IrfanView dialog	`A`
Main window Stop .GIF animation	`G`
Main window Thumbnails window	`T`
Main window Switch focus between thumbnails window and main window	`⭾ Tab`
Main window Cycle focus in the thumbnails window	`Ctrl` + `⭾ Tab`
Main window Minimize the IrfanView window	`M`
Main window Show/hide status bar	`Alt` + `↑ Shift` + `S`
Main window Show/hide toolbar bar	`Alt` + `↑ Shift` + `T`
Main window Show/hide menu bar	`Alt` + `↑ Shift` + `M`
Main window Show/hide window title and borders	`Alt` + `↑ Shift` + `C`
Full screen mode Show image as original size (1:1)	`1`
Full screen mode Fit only large images to screen	`2`
Full screen mode Fit all images to screen	`3`
Full screen mode Stretch all images to screen	`4`
Full screen mode (num lock) Scroll to center of image	`5`
Full screen mode Fit image height to screen height	`6`
Full screen mode Show / hide the mouse cursor in full screen mode (mouse reappears when moved)	`F11`
Full screen mode Toggle text display in full screen mode	`N`
Slideshow Add current image to slideshow	`F4`
Slideshow Start/stop automatic viewing (windowed slideshow)	`↑ Shift` + `A`
Slideshow Start slideshow with current directory and images	`Ctrl` + `W`
Slideshow Slideshow dialog	`W`
Slideshow Pause / resume an automatic slideshow	`Pause`
Tools and dialogs Capture dialog	`C`
Tools and dialogs Show image in HEX viewer	`F3`
Tools and dialogs Paint dialog	`F12`
Tools and dialogs Browse subfolders dialog	`Ctrl` + `B`
Tools and dialogs Effects dialog	`Ctrl` + `E`
Tools and dialogs Find	`Ctrl` + `F`
Tools and dialogs Create grayscale image	`Ctrl` + `G`
Tools and dialogs Edit multipage TIF file	`Ctrl` + `Q`
Tools and dialogs Resample dialog	`Ctrl` + `R`
Tools and dialogs Insert text into selection	`Ctrl` + `T`
Tools and dialogs Interactive screenshot tool	`Ctrl` + `Print Screen`
Tools and dialogs Focus the toolbar edit field	`↑ Shift` + `T`
Tools and dialogs Change canvas size	`↑ Shift` + `V`
Tools and dialogs Acquire / batch scan dialog	`Ctrl` + `↑ Shift` + `A`
Tools and dialogs Comment dialog (for JPG images)	`Ctrl` + `↑ Shift` + `M`
Tools and dialogs Set image as wallpaper - centered	`Ctrl` + `↑ Shift` + `C`
Tools and dialogs Set image as wallpaper - tiled	`Ctrl` + `↑ Shift` + `T`
Tools and dialogs Set image as wallpaper - stretched	`Ctrl` + `↑ Shift` + `S`
Tools and dialogs Set image as wallpaper - previous wallpaper	`Ctrl` + `↑ Shift` + `P`
Plugins Start OCR plugin on image or selection	`F9`
Plugins Show EXIF information	`E`
Plugins Filter Factory dialog	`K`
Plugins Open Adobe filters dialog (plugin required)	`Ctrl` + `K`
Plugins Show IPTC info	`Ctrl` + `I`
Plugins Email image	`↑ Shift` + `M`
Plugins JPG lossless operations (plugin required)	`↑ Shift` + `J`
Plugins Lossless JPG crop (Plugin required)	`Ctrl` + `↑ Shift` + `J`
Plugins Lossless JPG rotation - left (Plugin required)	`Ctrl` + `↑ Shift` + `L`
Plugins Lossless JPG rotation - right (Plugin required)	`Ctrl` + `↑ Shift` + `R`