It would be a good idea to go ahead and get some of them into a soil or compost mix. IF they are extra tiny it may be caused by having used perlite instead of soil. Are you giving them enough light? Are you using any kind of organic fertilizer? It is important to always make sure you plants get enough light and nutrients. I use mostly organic fertilizers mixed with plant water and soil. I use a little bit of a bunch of different fertilizers all at once and it gives me spectacular results and extremely high yields. I have been studying this subject for a long time and I have it down to a science. How much of which organic fertilizer I use depends on the age of the plants along with what plant type and also what signs the plants are showing me. The two most important things to do to get your little plants to grow fast and healthy is to make sure they get enough light and food. There are a lot of different ingredients you can add to water to make your plants grow fast.....waaay too many to list here. I have created a webpage to help people that describes various fertilizers that can be added to water and soil to make your plants grow faster, be healthier and yield more than ever before! You can check out my educational webpage at the link below. Happy gardening!

Here is a link that might be useful: website about organic fertilizer additives to make your plant grow faster,healthier and yield more than ever before!

Seedlings especially at that stage do NOT need fertilizer.
I think it's time to report the...

Hi shlacm,

Taz is correct, the seedlings DO NOT need fertilizer. The cotyledon leaves will provide the nutrient and energy needs of the seedling until the first true leaves emerge.

If you wish to transfer them to some SOILESS mix, you could do so, but you will need to be careful. I recently did that with some seeds I had germination tested in between sheets of wet paper toweling. I lost one out of nine of the seedlings. I really recommend that if you do transfer them before they get their first true leaves, that you put them in soiless seed starting mix, or soiless potting medium. (Notice, I keep saying soiless? It is pretty important.)

You can wait until the first true leaves emerge if you want to.

Bets

Here is a link that might be useful: How do I start tomatoes from seed?

Thanks Bets... yeah, I knew the greenthumb guy was full of "IT" and I basically knew I could wait to move them until they got true leaves, BUT wanted to be SURE! I also figured everyone would get a chuckle out of my expecting a giant seedling to pop out of those itty bitty tomato seeds, lol! I was even amused at myself, I mean seriously, I expected something the size of a zucchini sprout to emerge... obviously not a thought-out assumption on my part!!!