If you're looking for a free mockup generator with a big library of templates, Mockey is a great option. It's got more than 5000 templates for photorealistic product mockups, great for social media posts. It's got a drag-and-drop editor and AI-generated backgrounds, so you can whip up good-looking mockups in no time. The site offers unlimited free downloads, too, and adds new templates each week.
If you want more AI, Mokker has a lot of features geared for product photography, including background replacement and more than 100 templates. It's got a free plan with 40 photos, but otherwise it charges by the seat or by the photo. It's good for maintaining brand consistency and automating some of the editing work.
Last, Wepik is a free graphic design editor with a lot of customizable templates and AI tools like Text-to-Image Generator and a Social Media Scheduler. It's geared for small businesses and individuals, with flexible free downloads of designs in various formats. It's good for a variety of visual assets, personal or professional.