Write Google Ads copy with AI — Guide

What you’ll have at the end

Three ready-to-test Google Ads — each with three headline variants and two description lines. Not “professional service” copy. Copy that names what you actually do, for the customer who’s actually searching, with a reason to click yours over the next result.

Time on task: about twenty minutes if you know your offer. Thirty if you need to write down what makes you different first (which is time well spent anyway).

The mistake most people make

You paste “write me a Google Ad for my [business type]” into an AI tool. Back comes:

“Looking for reliable [service]? Our experienced team delivers quality results at affordable prices. Call us today for a free quote!”

You’ve seen this ad a hundred times. So has your customer. They scroll straight past it.

The problem isn’t the AI. The problem is the brief. “Reliable,” “quality,” “affordable,” and “experienced” are words every competitor is using — because every competitor is giving AI the same vague prompt. The AI doesn’t know what makes your business actually different, so it fills in with the words that sound business-like.

The fix: give the AI four specific inputs it doesn’t have by default.

What you need before you start

Four things, written down before you open the AI tool:

The search term your customer is typing. Not a broad category — the actual phrase. “emergency plumber Melbourne” or “bookkeeper for tradies” or “cafe fit-out designer.” If you’re not sure, check your Google Ads account for your best-converting search terms, or think about exactly what problem they’re Googling at the moment they’re ready to buy.
The one outcome they want. Not your service. The result they’re after. “A tap that doesn’t drip,” “books that are up to date before tax time,” “a café that seats fifty and looks worth the Instagram post.”
The one reason to choose you. Concrete, not vague. Not “quality” — “Same-day callouts, seven days.” Not “experienced” — “Twelve years fitting out hospitality venues, forty-three projects completed.” Not “affordable” — “Fixed-price quotes, nothing added on the day.” If you have three differentiators, pick the strongest one for this ad group; you can write additional ads for the others.
The offer or next step. What does clicking the ad lead to? “Book online in two minutes,” “Get a fixed price in 24 hours,” “Free thirty-minute site visit.”

If you’ve got those four things written down, the AI can write you something real.

The brief, ready to copy

Open your AI tool (ChatGPT, Claude, Codex — the prompt works the same in all of them). Paste this block and fill in the brackets with your four inputs.

You're helping me write Google Search Ads for one service.

The search term my customer is typing:
[the exact phrase they'd search]

The outcome they want:
[the result they're after — not the service name]

Why choose me over the next result:
[one specific, concrete differentiator — no vague words like "quality" or "reliable"]

The offer / next step when they click:
[what happens after the click — book online, free quote, free consult, etc.]

Please write 3 complete Google Ads. Each ad should have:
- 3 headline options (max 30 characters each — count carefully)
- 2 description lines (max 90 characters each — count carefully)

Constraints:
- Every headline must be able to stand alone if Google only shows one
- At least one headline in each ad should include or closely echo the search term
- At least one headline should state the differentiator specifically
- No "quality," "reliable," "professional," "affordable," or "experienced" — these words are too common to help
- Descriptions should end with the next step (book, call, get a quote)
- Australian English spelling

After the three ads, flag any headlines that are over the character limit so I can edit them.

The character-limit instruction matters. AI frequently writes headlines that are 33 or 35 characters. Google silently truncates them — your carefully chosen words get cut off mid-sentence.

What you’ll get back

Three ads, each with three headline options and two descriptions. Usually the first couple of headlines in each ad are the strongest; the third is a useful alternative to swap in and test.

A few things to expect:

The search-term headline will probably be solid — AI is good at working the keyword in naturally.
The differentiator headline is where AI tends to either nail it or go slightly generic. If it comes back with something vague, ask it to be more concrete: “The description I gave was ‘same-day callouts, seven days’ — write a headline that says that more directly.”
The descriptions will get the structure right but may need the tone adjusted. If your business is casual and direct, ask for a revision: “Make these less formal — we talk to tradespeople, not corporate procurement.”

What to always change by hand

Three things to edit before you put these into Google Ads:

The character counts. Even after telling it to count carefully, AI gets this wrong sometimes. Copy each headline into a character counter (Google’s own editor counts as you type) and fix any that are over 30.
Any claim you can’t back up. If the AI wrote “Same-day guaranteed” and you can’t actually guarantee that, cut the word “guaranteed.” You can still say “Same-day callouts available” — just make it true.
The call to action. Make sure the CTA in the descriptions matches the actual landing page. If the ad says “Book online in 2 minutes” but the landing page is a contact form that takes a week to respond to, that’s a trust issue. Match them up.

A quick check before you upload

Five things to verify before the ads go live:

Do all headlines read as complete, independent statements? (Google may show only one at a time.)
Are all headlines 30 characters or fewer?
Are all descriptions 90 characters or fewer?
Does the landing page match the promise in the ad?
Is your strongest differentiator visible in at least one headline per ad?

If yes to all five, upload and test. Run two or three variants — let Google rotate them and check which headlines get the best click-through rate after a few hundred impressions.

Where to take this next

Writing the ads is one part of the job. The other part — which campaigns to run, how to structure ad groups, how to set bids, how to read the search terms report and cut the wasted spend — is where most small businesses lose money without knowing why.

The full Google Ads workflow, set up inside Codex so it works on your real account with your real data, is part of the Codex for Business Owners workshop. You’ll leave with ads written, the campaign structure sorted, and a weekly check-in routine that takes ten minutes. See the syllabus →