What are the differences between a Nintendo 3DS and a Nintendo 3DS XL besides screen size?

I'm looking into buying a 3DS.

Besides Screen size and overall size, are there anymore differences between the regular and the XL version?

Also, can they both play old DS titles?

Solution 1:

A quick wikipedia search resulted in this:

Note: I have summarized and paraphrased. Source.

• 90% larger screens; the top screen is 4.88 in (124 mm) and the bottom one 4.18 in (106 mm).
• 86% longer battery life; 1750 mAh lithium-ion battery, lasting 3.5 to 6.5 hours compared to the previous 3 to 5 hours on 3DS games and 6 to 10 hours compared to the previous 5 to 8 hours on original DS games
• 46% heavier; 336 grams
• 4 GB SD card comes packaged with the 3DS XL instead of the 2 GB card included with the standard 3DS

To answer your question about original DS games, notice the last part of the second bullet point.

5 to 8 hours on original DS games

Hope that helps.