What to message a guy when he ignores you?

A gap of a few days after a good conversation usually means he's lost the thread, not that he's lost interest. Look at how the chat ended. If he asked you a question, the next move is his, and you're waiting on a reply he meant to send. If you asked a question and he answered it fully, he may be waiting for you to propose the next step, and your silence is now what's holding it up. If your last message was a flat line with no hook, the gap is more likely about momentum than about him.

Also check his activity if the app shows it. Someone who's active on the app but not messaging you is spreading his attention across a lot of people. That's a very different situation from someone who's deleted the app. Neither tells you what he thinks of you, but both tell you how much to expect from the next exchange.

Two kinds of message work well here. The first is a light callback: something specific from the earlier chat, paired with a simple question he can answer in one line. It shows you were paying attention, and it gives him something easy to reply to. A good callback is short, has no apology in it, and doesn't mention the gap at all. If it refers back to something he said and asks about it, you've got the right kind.

The second is a plain logistics nudge if you already had a plan. This is the message that moves the date forward instead of dragging the conversation backward. Be specific about a day or area, and leave him an easy way to say yes or no. Skip any reference to him going quiet, any question about whether he's still interested, and any line that sounds like you're checking his feelings. Those make the reply about the silence, and that's the one thing you want to avoid.

Wait at least a full day after your last message before following up, ideally two or three. Following up within hours reads as anxious. Waiting a week and then sending one reads as if you've been stewing. A single message is the right amount. If he answers warmly, keep the thread going at his pace. If he replies briefly, match that length and let the conversation take its natural shape.

If there's no answer after one well-timed follow-up, stop there. Don't send a second nudge, a question about whether he got the message, or anything with a hint of hurt in it. Let the match sit. If he comes back a week or two later with a normal message, respond normally. If he doesn't, you have your answer, and the most useful thing you can do is put your energy into someone who actually replies.