Google Chrome Canary now can auto change New Tab Page background with a new image every day if you enable “Refresh daily” switch in Background collection in NTP customization menu v2.
Current Chrome Stable offers customize button in New Tab Page to let you upload and set a custom image as NTP background or you can also select and use wallpapers available from Chrome backgrounds collection for the same: Landscapes, Textures, Life, Earth, Art, Cityscapes, Geometric Shapes, Solid colors, and Seascapes.

You can select an image in collection and set it as NTP background, if you’re bored of seeing same background image again and again, how it would be if Chrome changes the picture daily or offers an option for the same?
Chrome 70 Canary now offers “Refresh daily” switch in every background collection and is disabled by default. You can now enter a collection, select an image, and turn on the setting. A new image will be applied to NTP, and on the next day, it will be replaced with a random picture from the same collection from which you’ve chosen to refresh the Chrome new tab background daily.
Do note the switch is available when we covered Custom color picker but it didn’t work then and it’s now working as we noted the image on NTP was changed to another one automatically yesterday.
Automatically change Chrome New Tab Page background in Canary daily
1. Ensure you’re using the latest Chrome Canary 78.0.3879.0 or later, visit chrome://flags page
2. Search for “ntp”, in the search results displayed, select “Enabled” for “NTP customization menu version 2”
3. Relaunch the browser.
4. Open the new tab page, click on the pencil icon to open “customize this page” dialog.
5. Select Background, choose one collection from Landscapes, Textures, Life, Earth, Art, CityScapes, Geometric Shapes, Solid colors, and Seascapes,
6. Select an image, enable “Refresh daily”, click “Done” to apply the changes.

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