How to Write Google Ads Copy With ChatGPT (Without Wasting Your Budget)

Google Ads is brutally unforgiving about copy. You get 30 characters for a headline. Ninety for a description. Every word has to work. And if your ad copy doesn’t match what the person just typed into Google, your ad gets ignored — or worse, clicked by the wrong person who bounces immediately and costs you money anyway.

Most small business owners writing their own Google Ads do one of two things: they write bland, generic copy that says nothing different from every competitor’s ad, or they hire an agency that writes the same bland copy at $500 a month. AI gives you a third option: prompts calibrated to Google’s RSA format that generate sharp, specific, character-count-compliant copy in under 15 minutes.

What You’re Actually Writing

Google Search Ads use a format called RSA — Responsive Search Ads. You supply up to 15 headlines and 4 descriptions. Google’s algorithm tests combinations and learns which pairs perform best.

The constraints:

Headlines: 30 characters maximum (including spaces)
Descriptions: 90 characters maximum (including spaces)

These are firm limits. If your copy is 31 characters, it won’t run. Character count is non-negotiable, which makes AI-assisted copywriting especially useful — you can prompt for copy within the exact character limit and get working drafts without counting characters manually.

Three Types of Headlines (And Why You Need All Three)

Strong RSA campaigns mix three headline types. Google rewards variety, and more importantly, different headline types capture different buyer intents.

1. Keyword headlines — Echo what the person just searched. If someone searched “emergency plumber Canberra,” a headline that says “Emergency Plumber Canberra” tells their brain “this is the right result.” Simple, but powerful.

2. Benefit headlines — The outcome the customer gets. “Same-Day Bookings” beats “Book Online.” “Clean Without Chemicals” beats “Eco Cleaning Services.” Lead with the result, not the category.

3. CTA headlines — What to do next. “Call Now for a Free Quote.” “Book Online in 2 Minutes.” “Free Estimate — No Obligation.” Short, direct, tells them the next step.

Your 15 headlines should be roughly 5 of each type. This ensures Google can assemble combinations that work for different search queries.

The RSA Headline Prompt

I run a [business type] in [city]. I'm writing Google Search Ads 
for [specific service].

Write 15 RSA headline options. Include:
- 5 keyword-focused headlines (echo search terms like "[service] [city]")
- 5 benefit-focused headlines (lead with the customer outcome — e.g. 
  "Same-Day Bookings," "No Cancellation Fee")
- 5 CTA headlines (action-oriented — e.g. "Book Online Today," 
  "Call for Free Quote")

CRITICAL: Every headline must be 30 characters or under (including spaces). 
Count every character. Flag any that exceed 30 characters.

My key selling points: [list 3–5 — e.g. "same-day service," "family owned," 
"price match guarantee," "no call-out fee," "15 years experience"]

Format: numbered list. Show character count in brackets after each headline.

Review the output and count spot-check a few. AI occasionally miscounts — run any you’re unsure about through a free character counter online.

The Description Prompt

Descriptions do the job of convincing. They have more room (90 characters) to address an objection, add a specific detail, or reinforce the benefit.

Write 4 RSA description options for the same ad.

My business: [business type] in [city], advertising [specific service].
My key differentiators: [list 3–5]
Common objections or concerns my customers have: [list — e.g. 
"worried about the price," "not sure if they'll show up on time," 
"don't know if they're licensed"]

Each description should:
- Be under 90 characters (including spaces) — count carefully
- Address one objection OR reinforce one differentiator
- End with a micro-CTA if space allows ("Call today," "Book online")

Show character count in brackets after each description.

Running Your First A/B Test

Once your ad is running, you can test copy variants. Google’s RSA format does this automatically by rotating headline/description combinations — but you should also run deliberate variants to understand what works.

To test a specific angle:

My current Google Ad headlines are performing, but I want to test 
a new angle focused on [pain point — e.g. "reliability," "price," 
"speed"].

Write 5 alternative headlines for this angle. Under 30 characters each.

My business: [type] in [city]. The new angle: [describe the pain 
point or message you want to test].

Character count in brackets after each.

What to test first: benefit vs. CTA headlines. Run two weeks of data, compare click-through rates in your Google Ads dashboard, keep the winner.

What Good Google Ads Copy Actually Does

The copy in a Google Ad serves two functions that most business owners don’t separate:

1. Match the intent — Echo the search query so the person knows they’ve found the right thing. This is why keyword headlines matter.

2. Separate you from competitors — Everyone bidding on “electrician Melbourne” has “Electrician Melbourne” in their ad. What makes yours different? That’s your benefit headline and description doing the work.

A common mistake: running ads that are identical to competitors in every way except the business name. If someone searches “dog groomer North Sydney” and four ads all say “Dog Groomer North Sydney — Book Online — Friendly & Professional Service,” nobody wins. Be specific.

Run this prompt to sharpen your differentiation:

I run a [business type] in [city]. My competitors' Google Ads 
typically say: [describe what you see when you search your own 
target keywords — the common phrases, the generic claims].

Write 5 headlines and 2 descriptions that are distinct from these. 
Focus on what makes my business different: [list your real differentiators].

Under 30 characters per headline, under 90 per description. 
Character counts in brackets.

The Free Resource: Google Skillshop

Before you spend anything on Google Ads, take one free course. Google Skillshop (skillshop.google.com) offers free, self-paced certification courses for Google Ads. The “Google Ads Search” course covers everything from account structure to bidding strategy. It takes about 3–4 hours and the certification is free.

It’s worth knowing how the auction works before you start writing copy — because even the best copy won’t rescue a poorly structured campaign.

Download the Ads Copy Checklist

📋 Free Download: Google Ads Copy Checklist

Three parts: pre-writing (what to know before you open ChatGPT), the three headline prompts, and post-writing verification (count characters, check your landing page matches, verify nothing misleading got through). Cuts setup time to under 20 minutes per ad group.

[Download the free checklist →]