Short answer
A Performance Max asset generator writes the text assets for an asset group and plans its images. Google allows 3 to 15 headlines of up to 30 characters, at least one of them 15 characters or fewer, 1 to 5 long headlines of up to 90 characters, and 2 to 5 descriptions of up to 90 characters, one of which must be 60 or fewer. The business name can have up to 25 characters.
How to use the Performance Max Asset Generator
- Enter your business, the product or service this asset group is for, your audience and the final URL.
- Add the selling points you can prove and choose a tone.
- Generate the assets: 15 headlines, 5 long headlines, 5 descriptions with the short one marked, a business name and 2 display paths.
- Use the image brief to shoot or choose photos for the 1.91:1, 1:1 and 4:5 ratios, and the video idea if you plan to film.
- Copy the assets or download the CSV, then add them to your asset group in Google Ads.
What text assets does Performance Max need?
Each asset group needs its own set of text. These are the limits in Google's Performance Max specs and its page on text assets for Performance Max:
| Asset | Character limit | How many | The generator writes |
|---|---|---|---|
| Headline | 30 | 3 to 15, 11 or more recommended | 15 |
| Long headline | 90 | 1 to 5, 2 or more recommended | 5 |
| Description | 90 | 2 to 5, 4 or more recommended | 5 |
| Business name | 25 | 1, required | 1 |
| Display path | 15 each | Up to 2, optional | 2 |
Two rules catch people out. Google asks you to include at least one headline of 15 characters or fewer, and one description must be 60 characters or fewer.
Google's asset group setup guide calls that one the short description, and the Google Ads API rejects an asset group that lacks it (API troubleshooting).
The business name must exactly match your domain name or your legally verified business name, so check the suggestion before you use it. The call to action is automated by default, or you can select one from Google's list, so the generator leaves it to you.
How does the Performance Max asset generator work?
You describe the business, the product or service, the audience, the selling points you can prove, the final URL and a tone. Claude, Anthropic's AI model, drafts the assets on our server, and every line is measured against the limits above before it reaches you.
Each line is written to stand on its own, because you do not choose which headline appears next to which description. The generator marks the short description and keeps at least one headline at 15 characters or fewer.
For long headlines, Google's spec suggests at least 30 characters. Use that room for a full sentence rather than a stretched headline.
Which images and videos should you plan?
Alongside the text, the tool writes a short brief for each image ratio and one video idea. You still need real photos or footage, in the sizes from Google's page on image assets for Performance Max:
| Image | Recommended size | Minimum size | Count |
|---|---|---|---|
| Horizontal 1.91:1 | 1200 x 628 | 600 x 314 | Required, 4 or more recommended |
| Square 1:1 | 1200 x 1200 | 300 x 300 | Required, 4 or more recommended |
| Vertical 4:5 | 960 x 1200 | 480 x 600 | Optional, 2 or more recommended |
| Square logo 1:1 | 1200 x 1200 | 128 x 128 | Required |
| Horizontal logo 4:1 | 1200 x 300 | 512 x 128 | Optional |
- You can add up to 20 images per ratio and up to 5 logos, and image files can be up to 5120 KB.
- Keep the main subject in the center 80% of the image, which Google treats as the safe area.
- Text overlays are allowed in Performance Max, unlike other campaign types, but Google recommends at least one image without overlays for each aspect ratio (image asset requirements).
- A logo with a transparent background may be shown on white, so avoid a mostly white logo on a transparent background.
- Video is optional: 16:9, 1:1 or 9:16, 10 seconds or longer, up to 15 per asset group. If you add none, Google may auto-generate videos from your other assets (Performance Max specs).
The Google Ads Image Resizer crops one photo to all three ratios and builds both logo files in your browser.
Mistakes to avoid with Performance Max assets
- No short headline. "Emergency Plumbing" is 18 characters, so it does not count as the short one. "Plumber On Call" is 15 and does.
- Long headlines that are padded headlines. Use the extra room for a complete thought: the service, the benefit and who it is for.
- Repeated lines. Google's repetition policy covers asset text that repeats other assets, so give each description its own point.
- Leaving video to chance. Without a video, Google may build one from your assets. Script your own with the YouTube Ad Script Generator.
- Treating a clean check as approval. The tool checks limits and uses only the claims you give it. Google's review decides whether assets are approved.
Running a responsive display campaign instead? The Display Ad Copy Generator writes that smaller asset set.
Sources
- Performance Max campaigns specs and format requirements (Google Ads Help)
- About text assets for Performance Max campaigns (Google Ads Help)
- Step 4: Set up your asset group and assets (Google Ads Help)
- Performance Max troubleshooting (Google Ads API)
- About image assets for Performance Max campaigns (Google Ads Help)
- Image assets format requirements (Google Advertising Policies Help)
- Repetition (Google Advertising Policies Help)
Updated 2 October 2026 by the Paid Pilot team. Google Ads is a trademark of Google LLC; Paid Pilot is an independent agency.