Pictures from Canon t5 are low quality on iphone 6s?

The pictures I take on my Canon are really good and I usually put them on my laptop and then send them to my phone but the quality of the pictures once sent to my phone is so bad and it just doesn't look as hd as it does on my camera and laptop. Am i doing something wrong?

The resolution of the picture it is only as good as the screen resolution of the device you are viewing it on.

(If the resolution of the picture is higher and the viewer is lower it CAN ONLY show it at a lower resolution).

Make sure to not scale down the resolution when sending to your phone, e.g don't scale a 4K picture down to the resolution of you phone

Transfer the image to your phone. Then copy the image from the phone back to your computer. Then compare the images by opening both in some kind of image editing software on your computer. They should be the same. You can also check the file size. If the file sizes are the same, then the file is the same and it's the phone's display that's making the image look bad. If they're different in size, then it's likely that the app that your using to send the image to your phone is downsizing the image.

How the picture looks like on the computer monitor is how the picture really looks like. The LCD of the camera is too small that it tends to hide gross errors in exposure.

If you're not using a USB card reader to copy pictures from the camera to the computer then that's one problem.

If you're using an automated program to do the copying then that's the worse thing you've been doing so far. Use Windows Explorer or (Mac) Finder instead for total control.

If picture quality is bad on the computer monitor then blame yourself. Picture quality depends mostly on the skill of the photographer.

Whatever you are using to "send" the photos to your phone is downsizing them and/or reducing quality. Check the Settings menu to change the Export size and quality.