What you’ll be able to do

By the end of this you’ll have a speech that sounds like you, not like a template off the internet. Right stories, right order, right length. For a best man speech that’s usually about five minutes, roughly 700 words, and you can get a solid draft in under an hour if you’ve done the thinking beforehand. That’s the bit people skip, and it’s the bit that matters most.

Before you start

Here’s the thing nobody tells you: the AI can’t give you the good stuff. It doesn’t know that Dave once tried to propose a toast to the wrong bride at a different wedding. It doesn’t know that Sarah cried the first time she ate a bagel because it reminded her of her nan. You have to bring the stories. All the AI does is help you shape them.

So before you open any tool, get three true stories about the person or people you’re honouring. Not ten, not one. Three. Enough to build a shape without drowning the audience. Think about what actually shows who they are, not just what’s funny. A story where they were kind under pressure works better than a story where they fell over at a barbecue, even if the barbecue one gets a bigger laugh.

Then work out your practical limits, because these change everything about what you write. Who’s in the room? Grandparents, colleagues, kids? A wedding audience is different to a leaving do audience, obviously, but it’s easy to forget that when you’re deep in a funny anecdote. How long have you got? Five minutes is the rough target for a best man speech, which is about 700 words when you read it at a normal pace, not the pace you talk at when you’re nervous and rushing. And what’s the tone: warm and gently teasing, properly sentimental, mostly jokes with one serious moment near the end? Decide this now, because if you don’t, the AI will default to something bland and generic, and you’ll spend longer fixing that than you would have spent deciding upfront.

One more thing while you’re in this stage: work out what you’re avoiding. In-jokes nobody else in the room will get. Anything about exes. Anything that would embarrass the couple, even slightly, even as a joke. Write this list down. You’ll use it in a minute.

Get set up

You don’t need anything fancy for this. ChatGPT, Claude, Gemini, or Copilot will all do the job, they’re all capable of taking a rough set of notes and turning them into a structured speech. Pick whichever one you already have access to. If you’re starting from scratch, ChatGPT and Gemini both have free tiers that are more than good enough for this task.

If you want the result to sound like you rather than like a wedding speech generator, it’s worth trying ScriptGrain, which is one of ours. It’s built to measure your writing style from samples of your own writing, so instead of getting the same “hilarious yet heartfelt” tone every AI speech seems to land on, you get something that reads like you actually wrote it. There’s a free tier, so it costs you nothing to try before deciding whether it’s worth using again.

The honest alternative is just using ChatGPT or Claude directly and being very deliberate in your prompt about tone and voice, feeding it examples of how you actually talk. Both approaches work. ScriptGrain does more of that work for you; the general tools need more steering from you but get you most of the way there too.

Beyond the writing tool itself, two other things help. ChatGPT’s voice mode is genuinely useful for rehearsing out loud once you have a draft, because hearing it spoken back gives you a different sense of pacing than reading it silently ever will. And your phone’s voice recorder is the simplest tool on this whole list: record yourself reading the speech, check the time, done.

Try it yourself

Right, this is where you actually use the thing. The key is giving the AI everything it needs in one go: your stories, your constraints, and your no-go list. Don’t make it guess.

Here’s a prompt to generate your first draft:

I need a best man speech for my friend [name]'s wedding. It should be about 5 minutes long, around 700 words, warm with some gentle teasing but not mean.

Here are three true stories about him:
1. [story one, with enough detail that the point of it is clear]
2. [story two]
3. [story three]

Audience: mostly family and old friends, some work colleagues who don't know him well, a few young children.

Please do NOT include:
- Anything about his ex-girlfriends
- The nickname "Chalky" (long story, nobody else will get it)
- Any story that makes him or his new wife look bad

End with a toast to the couple. Write it so it sounds natural when spoken aloud, not like an essay.

Once you’ve got a draft, you’ll probably want to work on the structure separately, because the order of stories matters as much as the stories themselves. Here’s a prompt for that:

Here's a draft of my speech: [paste draft]

Can you suggest a better order for the three stories, so they build up rather than feel random? I want it to end on the most touching moment, not the funniest one, so the crowd is in the right mood for the toast.

And a third prompt, this time focused on making it sound like you rather than like a generic speech:

This speech currently sounds a bit formal. I talk in short sentences, I use a bit of dry humour, and I don't use big words. Can you rewrite this in that style, keeping all the same stories and structure: [paste draft]

A word on how to write for the ear rather than the page: short sentences work better than long ones. One idea per breath, roughly. If a sentence runs on for three lines when you read it back, split it. You can ask the AI directly to do this: “make the sentences shorter, one idea per line, like you’re talking rather than writing.”

Check the result

Once you’ve got a draft you’re happy with, the real test starts. Read it out loud. Not in your head, actually out loud, in the room you’re going to give it in if you can manage that, or at least standing up rather than sitting at a desk.

Time it with your phone while you do this. If it’s running long, that’s normal on a first pass, most speeches do. Cut, don’t rush; a five-minute speech read at rushed panic-pace stops sounding like five minutes and starts sounding like someone late for a train.

Check the landing points. Does the funny bit land where you expect? Does the sentimental moment actually feel sentimental when you say it out loud, or does it feel forced? You’ll know within the first read-through whether a line works or not, your gut is a decent judge here.

And then the bit that actually matters most: go through every single fact in the speech and ask, is this true, and is this kind? Every story, every detail, every claim about a person. If you’re not certain something happened exactly as written, either check it with someone who was there or cut it. This is the one part of the process where you can’t hand off the responsibility to the AI. It doesn’t know these people. You do.

Rehearse it out loud twice at minimum before the day. Once to check the timing and flow, once to get comfortable actually saying the words rather than reading them.

If it doesn’t work

The single biggest risk with using AI for this is invented detail. If your prompt is vague, the model will sometimes fill gaps with plausible-sounding specifics that never happened, a made-up nickname, a fictional shared holiday, a detail about how the couple met that isn’t quite right. It’s not trying to deceive you, it’s just doing what these tools do when the instructions leave room to guess. The fix is simple but non-negotiable: never let a fact stand in the final speech unless you know it’s true. Read every line and ask where it came from. If you can’t answer that, cut it.

There’s also a privacy angle worth thinking about. Don’t paste in anything genuinely private about the couple or your friend, financial details, health information, anything that was told to you in confidence. Most mainstream AI tools may use conversations to improve their models unless you’ve turned that off in settings, so treat the chat the way you’d treat a conversation with a stranger on a train: fine for anecdotes you’d tell at a party, not fine for anything sensitive.

Finally, watch for in-jokes. If you mention a nickname or a shared memory to the AI without full context, it might use it in a way that changes its meaning, or worse, repeat it back with a slightly wrong version of the story attached. Anything that only makes sense to three people in the room should either be explained fully in your prompt or left out of the AI’s hands entirely and written by you, by hand, afterwards.

Keep exploring

If you want the finished speech to sound properly like you rather than like a well-drafted stranger, have a look at “How to get AI to sound like me”. If a poem feels more fitting than a speech, or you want a short verse to open with, there’s “How to get AI to write a poem”. And if the whole idea of standing up and speaking in front of people has you rattled regardless of what’s on the page, “How to get AI to help me practise for an interview” covers a lot of the same rehearsal techniques that work just as well for wedding nerves as job nerves.

Sources and review notes

Review date: 15 September 2026 — every source above was opened and checked against the text on that date.

Disclosure: ScriptGrain is one of our products — this site is made by the same studio, Adapt Progress Evolve. We have tried to compare fairly, and the alternatives named are real and worth a look.