The reason they are tall like that is not because they are happy. They are hurting for more light and the elongated stem is them putting all their energy towards trying to get closer to whatever light source is nearby. It looks as though nearly all your seedlings are expressing this.

Those leaves at the top are the seed leaves, cotyledons, which supply nutrients to the plant until it's true leaves grow and start photosynthesizing. They should be very near the soil line, not way up in the air like that.

I am going to guess that you are using window light, which is very commonly done and just as frequently results in poor plant performance. Windows simply do not give enough light for growing seedlings.

I do not grow flowers, so I can't be certain on this, but with most vegetables you can bury that long stem right up to those seed leaves in a deeper container and then give them more light. Lots more.

Don't feel bad though, or get discouraged. This happens to a lot (I would guess most) who have ever first started gardening or growing from seed. If my old computer worked, I think I have some pictures of my first seeds started indoors, and they probably look worse then yours!

I hope these aren't still sitting on a heat mat. If so, remove them ASAP.

No they are not big enough to plant outside even if the weather permitted. As Zach said they are very leggy so I would transplant them ASAP into somewhat larger containers and bury all that stem. While you can transplant young seedlings to containers at any time most wait until they develop some true leaves just to make them easier to handle. I wouldn't wait on these as they are going to start breaking over, The weak stem can't hold up the head weight..

But unless you can solve the light issue I'm afraid they are just going to turn leggy again.

Good luck.

Dave

Those are definitely etoliated, and will need hardening off if you want them to have any chance of surviving outdoors. Here are some of my plants under a t5 light setup where the seedlings are generally within 20 inches of the light bulbs. You can use metal halides, HPS, LEDs, or anything with decent wattage.

For example, I have 4X 50 watt tubes, and I still feel like I would be better off with a stronger setup.

These are angled luffa and tomato seedlings.