Ad Platform Specs
Google Performance Max Specs
Performance Max is an asset group problem before it is a bidding problem. If you feed it the minimum, Google builds the combinations it can rather than the ones you want, and the placements you never intended to buy are the ones that spend. This is the checklist I fill before a campaign goes live.
| Asset | Character limit | Minimum | Recommended |
|---|---|---|---|
| Headline | 30 characters | 3 | 5 or more |
| Long headline | 90 characters | 1 | 3 to 5 |
| Description | 90 characters | 1 short plus more | 4 |
| Short description | 60 characters | 1 | 1 |
| Business name | 25 characters | 1 | 1 |
| Call to action | Selected from a list | 1 | Test manual against automated |
| Asset | Ratio | Recommended pixels | Minimum count |
|---|---|---|---|
| Landscape image | 1.91:1 | 1200 x 628 | 1, use 3 or more |
| Square image | 1:1 | 1200 x 1200 | 1, use 3 or more |
| Portrait image | 4:5 | 960 x 1200 | Optional, strongly recommended |
| Logo, square | 1:1 | 1200 x 1200 | 1 |
| Logo, landscape | 4:1 | 1200 x 300 | Optional |
| Video | Horizontal, square or vertical | Hosted on YouTube | 1, or Google auto generates one |
Notes
If you supply no video, Google will generate one from your images and it will usually be worse than anything you would ship yourself. Uploading even a simple ten second cut of existing footage takes the auto generated asset out of rotation and is the single cheapest quality improvement in the format.
Asset groups are the closest thing Performance Max has to ad groups, so use them as the segmentation layer. One asset group per product line or audience theme with its own creative and its own listing group keeps reporting readable and lets you switch off a losing theme without touching the campaign.
Brand exclusions and account level negative keywords are the guardrails that stop Performance Max spending your budget on branded search you would have won for free. Set them before launch, not after the first billing cycle.
Google changes Performance Max requirements, reporting surfaces and controls frequently, and the asset minimums have moved since launch. Verify against the Google Ads Help documentation before building an asset template.
Frequently asked questions
How many asset groups should a campaign have?
As many as you have genuinely distinct creative themes, and no more. Splitting for the sake of it starves each group of the conversion volume the bidding needs.
Can I see where Performance Max actually spent?
Partially. Reporting has improved with asset group, search themes and channel level insight, but it is still less transparent than search campaigns. Treat placement level questions as directional rather than definitive.
Do I need portrait images?
They are optional and I always add them. Without a 4:5 asset you give up quality inventory on vertical placements, which is a meaningful share of the impressions.
Official sources
Platforms change specifications without notice. Check the primary documentation before a launch that depends on an exact value.
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More Ad Platform Specs
Google Ads Specs
Google Ads character limits for responsive search ads, Performance Max assets, image sizes and video requirements.
Meta Ads Specs
Facebook and Instagram ad specs: image and video ratios, text limits, placement requirements and file constraints.
LinkedIn Ads Specs
LinkedIn ad formats and specs: single image, video, carousel, document and message ads with character limits.
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TikTok ad specs for In-Feed ads and Spark Ads: video dimensions, length, text limits and safe zone guidance.
Display Ad Sizes
Standard IAB display banner sizes, the highest inventory formats, and file size limits for HTML5 and static display ads.
YouTube Ads Specs
YouTube ad formats, skippable and non skippable length rules, bumper limits, companion asset sizes and the text fields for each format.