Nick here from Shopify.
Thanks for reaching out about this, it can be a little awkward at times. For example, if you are bulk selecting all of the products and then changing page it might not work properly. Often you would need to do this aspect page by page which is not ideal. There is however a workaround you could look into.
The workaround would involve you exporting your products via a CSV file, editing your products in bulk (here is where you would remove the ones you don't want moving forward) and importing the new updated CSV file back into your store where the 1,500 + products would no longer be there. Something to note with this method is to make sure you select the Overwrite existing product option or it will not work.
I know this might not be completely ideal, but other than deleting the products on a page by page basis, this is the quickest and most efficient method for removing such a large number of products.
Hope it helps!
All the best, Nick
Thanks a lot for getting back.
Although I tried your method (to overwrite) it actually still duplicates the products.
Even worse, it does not upload all the products. I have around 2000 products but it uploads around 100-200 products only.
I understand it might take longer but even after one night the products have not been uploaded.
For this task, you could use Excelify.io App. We have a great tutorial on how to delete a large number of items with ease - https://excelify.io/2017/09/28/shopify-bulk-delete-products/
You can also use it to create and update various items in your Shopify store without replacing existing items.
If you have further questions about it you can contact us by any means listed in our Contact Us page - https://excelify.io/contact-us/
Maybe you should try these steps on this article to delete unwanted or unused files on Shopify. Hit like if it could solve your problem