Google Ads Ad Preview Tool
and RSA Character Counter

Responsive search ads in plain English

On the Search Network, Google Ads no longer has you write one fixed ad: you supply assets and Google puts them together. A responsive search ad (RSA) takes 3 to 15 headlines and 2 to 4 descriptions. For each search, Google picks a combination of up to 3 headlines and 2 descriptions, in the order it considers most relevant. Headline 1 and description 1 usually show; headline 2, headline 3 and description 2 are not guaranteed. Unused headlines can also appear as link-based assets, and descriptions can fill in link descriptions, so a well-written asset may work more than once.

This tool helps you prepare those assets before you enter them: it counts characters live, turns the counter red over the limit, shows the ad as it could appear and flags what drags down Ad Strength.

Google Ads character limits

In double-width languages (Chinese, Japanese, Korean), each character counts as two, and the counter follows the same rule. The display URL is built from the final URL’s domain followed by the two paths, for example exampleplumbing.com/plumber/austin.

How to use the Google Ads preview tool

1. Enter at least 3 headlines, ideally 10 to 15, each with a different idea: keyword, benefit, proof, offer, call to action.
2. Add 2 to 4 descriptions. Each one has to stand on its own, since Google may show only one.
3. Fill in the final URL and, if you like, the two display URL paths.
4. List your ad group keywords to check that each one appears in full in at least one headline.
5. Click Another combination to rotate headlines and descriptions, on desktop and then on mobile.
6. Fix what the checks flag, then copy the CSV export to get the ad reviewed or to archive it.

How many combinations? The formula

Without pinning, the number of ordered arrangements of 3 headlines out of n and 2 descriptions out of m is:

combinations = n × (n − 1) × (n − 2) × m × (m − 1)

With 15 headlines and 4 descriptions: 15 × 14 × 13 × 4 × 3 = 32,760 arrangements. With the minimum, 3 headlines and 2 descriptions: 3 × 2 × 1 × 2 × 1 = 12. Pinning shrinks that number fast: pinning 2 headlines to position 1 leaves 2 choices there, then 13 × 12 for the other two, so 312 headline combinations instead of 2,730. Google does not serve every variation equally, but the more distinct assets you give it, the more it has to test.

Pinning: when it helps, and what it costs

Pinning locks a headline or description to a position. Text pinned to headline 1, headline 2 or description 1 always shows; text pinned to headline 3 or description 2 does not appear in every ad. Google says pinning is not recommended for most advertisers: it reduces the number of combinations and can affect Ad Strength.

• Save it for required text (a legal disclaimer, a mandated name) or one key headline.
• Pin 2 or 3 variations to the same position rather than one headline, so Google still has options.
• Do not pin every position: unpinned headlines would never show.

The tool applies these rules: the preview respects your pins and the combination count updates.

Worked example: an emergency plumber in Austin

The default example has 9 headlines and 3 descriptions. "Emergency Plumber in Austin" (27 characters) carries the keyword; "Drain Cleaning & Water Heaters" uses all 30 characters. A first try at it, "Drain Cleaning & Water Heater Repair", hits 36 characters and turns the counter red: Google Ads would not accept it. The second description, "Upfront pricing before any work starts. No overtime fees on nights, weekends or holidays.", lands at 89 characters.

With 9 headlines and 3 descriptions, the ad offers 9 × 8 × 7 × 3 × 2 = 3,024 arrangements. Adding 6 headlines and one description, to reach 15 and 4, multiplies that by more than ten.

Best practices

• Put each important keyword in full inside a single headline: that is what Ad Strength looks for. Keywords longer than 30 characters go in descriptions.
• Vary the angles: Google recommends unique headlines and descriptions that do not repeat the same words or ideas.
• Read several combinations out loud: if two headlines repeat or contradict each other when they sit side by side, rewrite one of them.
• Aim for at least 2 responsive search ads rated Good or Excellent in each ad group.
• Add at least 6 sitelinks: Google includes them in its Ad Strength recommendations.
• Match the ad and the page: the promise in the headline should show up at the top of the landing page.
• Remember that Ad Strength is a guidance metric: it does not decide whether your ad can serve.

Common mistakes

• Writing 15 versions of the same headline ("Plumber Austin", "Austin Plumber", "Your Austin Plumber"): Google sees one idea repeated.
• Putting key information in headline 3 or description 2, which do not always show.
• Writing headlines that only make sense together: each one has to read alone, in any order.
• Pinning everything to stay in control: the ad loses its combinations.
• Leaving the paths empty: /plumber/austin reassures more than a bare domain.
• Sending the click to the homepage instead of a page built for the offer.

Once the ad is ready, size the spend with the Google Ads budget calculator (and our guide to how much Google Ads costs a small business), then track what the clicks turn into with the conversion rate calculator: your conversion rate tells you whether the ad and the page keep their promise. For organic results, switch to the SERP preview tool. New to the platform? Start with Google Ads for small business, or see how we manage Google Ads.