Start with the input source. Some tools start from a topic, while others accept a LinkedIn post, tweet, Reddit post, URL, image, or document. If your content already exists, the quality of the slide-by-slide split matters more than the number of templates.
Then check export. For LinkedIn, a multi-page PDF is the most direct format. PNG files are useful when you want to reuse slides elsewhere. LinkedIn recommends PDF to preserve upload quality; see its document sharing guidance. Finally, check brand consistency: colors, fonts, assets, templates, and how fast you can edit after generation.