- What is the maximum image file size that I can upload to the webpage? I have 2-3 MB image sizes.
There is no real limit. Common sense says that you would only load an image that is practical to display on a screen, but you've probably seen things like "high resolution image from the mars rover" where it displays seemingly millions and millions of pixels of data.
2. What is the recommended and best image resolution to use in webpages? Does it make a difference if i have 72 dpi resolution or a 600 dpi resolution image?
DPI on the web makes absolutely no difference. It is a printing issue, and not relevant for web images. Set it to 1dpi, 72dpi, 600dpi, no difference.
3. Does high resolution and high image file size affect the page ranking and performance of the website? if yes, in what way?
Not to my knowledge.
4. How can i have a high resolution image with fixed pixel dimension? For example, the image should have 770x200 pixel dimension, can i increase the resolution of the image without changing or altering the dimension? How can i do this in Photoshop?
On the web, all there is, is the number of pixels in the image. You're describing something that doesn't exist - altering "resolution" while leaving the image size in pixels the same. There is no such thing.