What these tools do not replace
Raw processing, colour grading and retouching belong in a proper editor. Raw files (CR3, NEF, ARW, DNG and so on) need to be exported from your raw software first; the tools here work on the JPG, TIFF, PNG or HEIC that comes out of it.
Web exports that look good
For online galleries, 2048 pixels on the long edge at quality 80 to 85 is a good balance: sharp on large screens, quick to load, and small enough that full-resolution theft is not worth much. Export in sRGB; wide-gamut files without a profile look flat in many apps.
If you have ever wondered why a print lab insists on 300 DPI, DPI is mostly a label explains what the number really controls.
Questions people ask
Can I convert RAW files here?
Not yet. Export a JPG or TIFF from your raw processor first.
Does removing EXIF reduce photo quality?
No. The metadata is removed without re-compressing the image, except for photos that rely on a rotation tag, which are re-saved upright at high quality.
What size should photos be for Instagram and the web?
Around 1080 px wide for social feeds, 2048 px on the long edge for web galleries.