You said something that came out wrong. Or you did something you should not have. Either way the other person is hurt and you are here trying to figure out how to put something into words that actually reaches them.
Most sorry messages fail not because the person does not mean them but because they are written from the wrong angle. They focus on the writer's regret rather than the other person's experience. They explain more than they acknowledge. They say sorry in a way that somehow still makes it about themselves.
Here is what actually works.
Start with them, not with yourself
The instinct is to open with your own feelings. "I feel terrible about what I said." The problem is that this puts your emotional state at the center of a message that should be centered on the person you hurt. They have to read about your guilt before they even get to the acknowledgment of what happened to them.
Start with them instead. Their name. What they experienced. "What I said at dinner hurt you, and it should not have." This is harder to write because it requires you to look directly at what you did without any buffer. That is exactly why it lands differently than the version that leads with your own feelings.
Name the specific thing
The more specific you are about what you did, the more the other person feels actually seen rather than receiving a generic apology that could have been sent to anyone. "I'm sorry I said that in front of everyone" lands differently than "I'm sorry for how things went." One shows you understand exactly what hurt them. The other could mean almost anything.
Being specific also means you cannot hide behind vagueness. It requires you to say out loud the thing you did, clearly, without softening it into abstraction. That accountability is part of what makes the apology real.
Keep it short
A sorry message does not need to be long. In fact long apologies often backfire because they feel like the writer is processing out loud, asking the other person to hold their emotions while also dealing with their own hurt.
Four or five sentences covering what you did, that it was wrong, and that you understand how it landed is usually enough. You are not trying to resolve everything in one message. You are trying to open a door.
Do not explain unless they ask
Save the context for a conversation. The apology message is not the place for "here is what I was going through that made me act that way." Even if the context is real and relevant, putting it inside the apology makes it look like you are already defending yourself before they have even had a chance to respond.
When the words do not come
Sometimes you know you need to apologize and the first sentence simply will not come. unsaidit helps you find that opening line based on your specific situation. You describe what happened and it gives you options that sound like you rather than like a template.