What to do when a guy stops texting you back?

Before you decide what to send, look at the pattern. Did he message first most days, or did you usually start it? Did his replies get shorter in the last few exchanges, or did they stop abruptly while the conversation was warm? A guy who fades mid-flow after a good exchange is often just distracted, because texting is easy to drop when life gets busy. A guy whose replies had been thinning out for days was probably losing interest before he stopped entirely. Those two situations call for different levels of effort from you.

Also check whether he ever suggested meeting or made any plan. If he did, the silence is more likely a flake or a real change of mind, and you can reference the plan directly. If there was no plan and the texting was mostly banter, there is less to salvage and you should keep your expectations loose. Reading this honestly will tell you whether a single follow-up is worth sending at all.

The strongest kind of follow-up picks up a specific thread from before he went quiet. A question he asked you, a story he told, a plan you were both half-making. Your message should be easy to answer in one line, because a guy who has lost the thread needs a way back in that doesn't require him to rebuild the whole conversation. A message that makes sense without any context, like a funny comment about something you just saw that reminded you of him, works too, as long as it's light.

What to leave out is anything about the gap itself. Don't count the days, don't say you noticed he went quiet, and don't ask whether something is wrong. Those lines make the silence the topic, and he now has to address your feelings before he can answer anything else. Keep the focus on the conversation you were having.

Timing does a lot of work here. If you have been waiting several days and you reach out late at night, the message will read as needy even if the words are fine. Send your follow-up in the middle of a normal day, when a reply would be easy for him to give without it meaning anything. One follow-up is a reasonable amount. If he answers, match his energy and keep it moving. If he doesn't answer after a week or so, that is your answer, and sending a second message usually just makes you look like you are chasing.

Stop when you feel the urge to check whether he's read it, or when you start drafting a longer message to explain yourself. That is the point where you are no longer keeping the door open. You are trying to force a response, and the response you get back will rarely be the one you wanted.