CREATIVE COMMONS ZERO (CC0)

1. Pexels
2. Gratisography
3. Snapography
4. Magdelaine
5. Unsplash
6. Pixabay
7. Stokpic
8. Cupcake
9. Life of Pix
10. Splashbase
11. SkitterPhoto
12. CreativeCommons.photo
13. Freely Photos
14. Barn Images
15. StockSnap
16. Bara Art
17. 1 Million Free Pictures
18. SplitShire
19. Made In Moments

CREATIVE COMMONS ATTRIBUTION (CC BY)

1. Picjumbo
2. AuthenticSnaps
3. Supermfamous Photos
4. Free Food Photos
5. ISO Republic
6. DesignerPics
7. Raumrot
8. Titania Foto
9. Goodstock

CC ATTRIBUTION SHAREALIKE & CC ATTRIBUTION  NONCOMMERCIAL

1. IM Creator (CC BY-SA 2.0)
2. Lock & Stock Photos (CC BY-SA 4.0)
3. Foodie’s Food (CC BY-SA 2.0)
4. KaboomPics (CC BY-NC 4.0)
5. GIMME5 (CC BY-NC 4.0)