How to Write Google Ads Copy with AI: A Prompt Workflow

What You Will Deliver

This workflow produces Google Ads copy in five prompts: define the goal, profile the audience, list the selling points, write 30-character headlines, and write 90-character descriptions. Google enforces strict length limits (headlines up to 30 characters, descriptions up to 90), so the prompts are built to respect those caps rather than asking the model to “write ad copy” and hoping it fits.

You stay in control of claims and compliance. AI drafts; you verify the offer is real and the wording meets Google’s policies. For why generic marketing templates fall flat versus targeted ones, see generic vs targeted marketing prompts.

Step 1: Define the Campaign Goal

State the single action you want the click to produce. Vague goals produce vague ads.

You are a Google Ads copywriter. Campaign goal: [GET A FREE TRIAL / BOOK A DEMO / BUY X].
Product: [ONE SENTENCE DESCRIPTION].
Brand voice: [PROFESSIONAL / FRIENDLY / BOLD].
Return: one sentence stating the single user action the ad must drive, and the one proof point we will lean on.

Save that sentence. Every headline and description below must push toward that one action. A concrete example: for a project-management tool, the goal might be “get a 14-day free trial” and the proof point “used by 12,000 teams.” That single sentence then disciplines the whole ad set — if a headline does not move someone toward a trial, it gets cut. Avoid goals like “build awareness,” which cannot be measured in a click and produce vague copy.

Step 2: Profile the Audience

Audience detail is what separates a clickable ad from a wall of text. Give the model a persona, not a demographic label.

Audience for [PRODUCT]:
- Job role / life situation: [e.g. solo founders, new parents]
- Top frustration: [what annoys them today]
- What they fear losing: [time / money / status]
- Where they are in the funnel: [cold / considering / ready]
Write 3 one-line audience insights an ad should speak to. No copy yet.

These insights become the emotional hooks in your headlines. The tone guidance in choosing AI tone and persona helps you pick the right voice for each insight.

Step 3: Extract the Selling Points

Turn features into benefits the reader cares about. List the top three with proof.

From these features: [LIST 3-5 FEATURES]
Rewrite each as a benefit with a proof element (number, guarantee, or social proof).
Format: Benefit -- Proof.
Return the top 3 only, ranked by likely impact on a cold audience.

Keep this list visible. Your ad copy will pull directly from it, so the claims stay grounded in something true.

Step 4: Write Headlines (Max 30 Characters)

Headlines are the hardest constraint. The prompt must count characters and reject anything over the limit.

Write 10 Google Ads headlines for [PRODUCT] pushing [GOAL].
Rules:
- MAX 30 characters each. Count them.
- Each must include a benefit or a number or a keyword.
- Vary the angle: 3 with a number, 3 with a pain point, 4 with the offer.
- No clickbait that the landing page cannot support.
Return a numbered list. After each, put the character count in brackets like [27].

Pick the 3 to 5 strongest. If any exceed 30 characters, drop a word or use a shorter synonym — never let the model “round down” the count.

Step 5: Write Descriptions (Max 90 Characters)

Descriptions expand the headline with a reason to click. Same strict counting applies.

Write 4 Google Ads descriptions for [PRODUCT], supporting the headlines.
Rules:
- MAX 90 characters each. Count them and show [count] after each.
- Each must end with a soft call to action (e.g. "Start free", "See plans").
- Include one proof point from: [PASTE BENEFIT LIST].
- Match the [BRAND VOICE] from step 1.
Return numbered, with character counts in brackets.

You now have a full ad set: goal, audience, benefits, headlines, descriptions. Before you publish, run a compliance check — confirm the offer is real, no capitalized words that trigger policy flags, and the landing page matches the promise. If the copy reads flat after generation, the rewrite technique in ChatGPT rewrite vs edit prompts shows how to sharpen voice without losing length.

From Draft to Live Ad

Once you have headlines and descriptions, load them into the Google Ads editor and let the platform’s own character counter confirm the limits — never trust only the model’s bracketed counts. A good practice is to keep the three strongest headlines pinned so they always show, while the rest rotate for testing. Review the set against your landing page: if the headline promises “free,” the page must offer free, or the ad gets disapproved and your Quality Score drops. After launch, watch the one metric that matters for this workflow — conversions per impression — not just click-through rate, because a clever headline that attracts the wrong click wastes budget.

Final Deliverable Checklist

Tips for Higher CTR

Small wording changes move click-through more than new concepts. Test a number against a question, and a benefit against the brand name, since different audiences respond to different hooks. Keep a spreadsheet of which headline angle won in past campaigns and feed the winner pattern back into Step 4 as a constraint (“favor benefit-led angles like the last winner”). Also reserve one headline for the exact keyword you are bidding on, because matching the search term can lift Quality Score and lower cost per click.

Common Pitfalls

1. Trusting the model’s character count. Always verify in a counter; it rounds down.

2. Making claims the page can’t back up. Google disapproves and trust drops.

3. One generic headline repeated. Vary angles to find the winner in testing.

4. Skipping the audience step. Demographic labels (“women 25-34”) produce bland copy; insights produce clicks.

Sources & Notes

Copy workflow tested with ChatGPT (GPT-4o) and Claude 3.7 in October 2026. Character limits (headline 30, description 90) reflect current Google Ads specifications and should be re-checked in the Google Ads editor before launch, as limits can change. Category mapping follows the guunn.com AI Prompts plan (Marketing = 959). No ads were created and no APIs were called during article creation; prompts are copy-paste text for the reader to use in their own ad accounts.