Which tool to choose
You don't need to subscribe to anything to get started. Choose based on what you're actually writing.
For ads, slogans, social captions, and short promotional posts: ChatGPT's free plan covers the case. The free limit is real but manageable: free users get about 10 messages every 5 hours on the default model, then the responses drop to a lighter mini version. For writing four or five ads there's plenty.
If you want text that doesn't "sound like AI": use Claude (from Anthropic), also free on web, iOS, and Android. It tends to produce more natural writing, less recognizable as machine-generated. It's the right choice when tone matters more than quantity, for example for the voice of an artisan or personal brand.
If you run paid campaigns and want to predict which ad performs best: here a dedicated tool makes sense. Copy.ai works well on ad creatives and short content like landing pages and headlines; Anyword assigns a predictive performance score and steers the generation toward return on investment. They're paid and are only useful if you manage real ad budgets: for 90% of readers, free ChatGPT or Claude is the better move.
The operational advice: start free. Switch to a paid plan only when the free one starts blocking your real work, namely for clients' content, high volumes, or integration into your workflows.
How to do it
From a browser or the app the path is the same: open the tool, paste the prompt, refine.
- Gather four pieces of information before writing: what you sell, to whom (the typical customer), what the concrete offer is (discount, deadline, bonus), and where the ad runs (Instagram, Google, flyer, email).
- Open ChatGPT or Claude and paste the prompt below, putting your data in place of the text in quotes.
- Read the three variants. Feedback: if all three say generic things ("quality product", "the best on the market"), you didn't give specific enough data. Go back to point 1 and add real numbers and details.
- Choose the best variant and ask: "Shorten by 30%, cut every adjective that isn't provable with a number."
- Check the facts by hand: prices, dates, percentages. The AI can get them wrong.
The operational syntax, ready to paste:
You are an advertising copywriter. Write 3 ad variants for this case:
- Product/service: "evening yoga course at a studio in Bologna"
- Typical customer: "office workers 30-45, stressed by work, little time"
- Concrete offer: "first trial lesson free by June 30"
- Channel: "sponsored Instagram post"
Rules:
- Use the PAS formula: Problem, Agitation, Solution
- Maximum 4 lines per variant
- Direct and warm tone, use the informal "you"
- Close each variant with a clear call to action
- No generic adjectives like "best" or "exceptional": use concrete benefits
After the 3 variants, suggest for each a headline of maximum 6 words.
Replace the four fields in quotes with your case and run it. The PAS formula (Problem-Agitation-Solution) and its sibling AIDA (Attention-Interest-Desire-Action) are the structures that hold up almost every ad that works: you touch a pain, make it vivid, offer the way out.
A concrete example
Marco runs a small bicycle shop and wants to push the spring tune-up service. He pastes the prompt, replacing the fields: product "complete bike tune-up at 39€", customer "urban cyclists who haven't touched the bike in months", offer "free brake check included until April 15", channel "local Facebook post".
ChatGPT returns three variants. The second starts like this: "Has your bike been sitting in the cellar since October? Rusty chain, mushy brakes, flat tires: jumping back on out of nowhere is a risk. Complete tune-up at 39€, brake check included free until April 15. Book: we reply same day."
Marco shortens the first sentence, checks that 39€ and the date are right, adds the WhatsApp number. Publishes. The PAS structure did the work here: it named the problem (idle bike), made it concrete (mushy brakes = risk), gave the solution with a deadline. Total time: seven minutes.
When it does NOT work (and how to fix it)
If the AI invents prices or dates
This is the number one risk. The worst mistake is publishing the first draft without changes: always check the output, because the model can invent information. Don't let it be the one to "remember" your price. Write it yourself in the prompt and eyeball every number before publishing.
If all the ads sound the same and generic
It means the prompt was thin on detail. Add a concrete, verifiable element: a number ("used by 1,200 customers"), a sensory detail, a typical customer objection to dismantle. Your stories, the brand voice, and what only you know are what separate the copy from the pile: put it in the prompt and the output stops sounding anonymous.
If you've run out of ChatGPT's free messages mid-job
At the limit (about 10 messages every 5 hours) the chats switch on their own to the model's mini version until the reset. Two immediate fixes: continue on free Claude in parallel, or stay on the mini version, which for short copy holds up just fine, until the limit resets.
If the text is good but too long for the format
Ads have hard character limits (Google, Instagram, SMS). Ask explicitly: "Rewrite within 90 characters including spaces, keep the call to action." Have the tool count the characters, but double-check yourself with a counter: on precise counts the AI is off by a few units. You'll find a free counter in any text editor or by searching "character counter" online.
A tip from someone who actually uses it
Never ask for just one version. Ask for three or five and use the AI as a generator of different angles, not as the final author. The value isn't the first response: it's being able to say "variant 2 has the right opening, 4 has the better closing, merge them." You stay the director who chooses and cuts. The ad you publish should always pass through one last round of your manual scissors: that's where the voice that sets you apart from competitors using the same tools comes in.
Frequently asked questions
Which prompt works best for Google ads?
Specify the exact format in the prompt: "3 headlines of maximum 30 characters and 2 descriptions of maximum 90 characters, each with a different keyword". Google rewards relevance, so also indicate the word people type to search for you. Then verify the counts by hand.
Can I use AI for free without a credit card?
Yes. Both ChatGPT and Claude have a real free plan: with free Claude you talk with the model on web, iOS, and Android, submit images and documents to it, and use one of the recent models. Many dedicated copy tools also include a free plan or a trial, so you test them before committing to a subscription.
Is it worth paying for a subscription to Jasper or Copy.ai?
Only if you produce copy in volume or manage multiple clients. At that scale the value is there: higher word limits, brand voice customization, SEO analysis, collaboration tools, more polished output. For a shop or a freelancer who writes a few ads a week it's an expense that doesn't pay off: the free plan is enough.
Doesn't the AI risk making my ad the same as my competitors'?
It's the right fear, and the answer is yes, but only if you use the prompt on the fly without any data of your own. These models recombine words from their training data: without your input they won't invent an angle that doesn't already exist in your materials. The differentiation is on you: your brand's story, a figure only you have, a tone that resembles you. The AI writes the structure, the uniqueness you decide. Those who publish the first draft get interchangeable ads; those who rewrite it starting from what's their own don't.