- IQDB: http://iqdb.org/
A multi-service image search that allows you to search multiple sites for image duplicates (can also be used for seeing how an image is tagged across other sites).
- SauceNao: https://saucenao.com/
An image search site that finds the source of Pixiv/DA images and other useful source information. Be careful of people posting images that do not belong to them on certain sites like Deviantart, as this can be picked up by Saucenao as the source.You can download the Saucenao extension for Google Chrome/Firefox here. This extension allows you to quickly right-click images and search using imdb, SauceNao and Google Images.
- CapitaliseMyTitle: https://capitalizemytitle.com/
Useful for capitalising English source titles correctly if you are unsure.
- Translation Tools: For help translating names and titles, see Translating Tools.