Can I istall a SSD in an iMac late 2013, 21in?

I would just replace the stock HDD with a 2.5" SSD as many above have suggested. I did a recent 3.5" HDD > 2.5" SSD upgrade in a 2007 24" iMac using this adapter which was perfect: http://www.amazon.com/gp/product/B00UN550AC

I've built and been inside plenty of computers for years, so it wasn't that difficult.

But these iMac are not that easy to get into.

I do have a 2013 27" iMac with Fusion drive, that I may upgrade the stock 128GB SSD once the AppleCare expires. This looks like the needed adapter to use a standard mSATA with the existing proprietary Apple connector:

http://www.pc-adapter.net/products/769.html

http://www.ebay.com/itm/Sintech-M-2-NGFF-18pin-adapter-as-SSD-for-2012-MACBOOK-A ir-MD223-224-MD231-232-/321487109320

Then again, maybe not. And it seems the ifixit picture is incorrect, so who knows what's really in there.

1. You have to get into that iMac, which is plenty involved. 2. at that point, swapping existing HDD should be straightforward. 3. to get to the ssd, a whole lot more is involved, including risk of shock/electrocution from the power supply 4. if you get that far, you better hope you have the right ssd and adapter. or all of this will be for naught.

If you do plan on opening the iMac, based on your comments, you should stick with 1. and 2.

I strongly agree with Woodmeister. The external SSD is the route I am planning to go. However perhaps the Apple Store Wizards could install the internal SSD for you? As an aside, I never wanted an iMac, ever, not no way, not no how, but the budget demanded otherwise. Else this would be a Mac Pro, it's such a cute little thing. Why, well why climb Everest? 🙂