Google Ads Performance Max Specifications

Performance Max is a new goal-based campaign type that allows advertisers to access all of their Google Ads inventory from a single campaign. It’s designed to work complimentary with your keyword-based Google Ads Search campaigns and help achieve more conversions across all of Google’s channels YouTube, Display, Search, Discover, Gmail, and Maps.
‘Smart Shopping’ campaigns and ‘Local’ campaigns will upgrade to Performance max sometime next year.
Performance Max will deliver more conversions and value by optimizing performance in real-time and across all available channels.
Performance Max will show as a campaign type selector if you choose Sales, Leads, or Local Store visits and promotions.
Advertisers that will utilize Performance Max should expect:
New audiences unlock across Google’s network
Better performance against goals
Transparent insights
Better automation output
Simple campaign management
Easy ads optimization
New customer segments
Data-driven attribution across all available channels
Better machine learning models
Better asset reporting
New insights
Before you consider Performance Max campaigns the Google Ads account should:
Have specific advertising and conversion goals
Have functioning conversion actions
Have an understanding of how Smart bidding works
Have quality data
Have high-quality texts
Have high-quality media
Have Account-level brand safety lists
Specifications
Performance Max campaigns have some unique specifications regarding assets that can be found here
Note that YouTube videos should be 10 seconds or more. This makes bumper ads [up to 6 seconds and region allowing] not eligible.
The screenshot is taken directly from the Google Ads API guidelines

For advertisers that aren’t versed in API, the guidelines are as follows
Asset
Recommended asset guidelines
Images
You can add up to 20 images
Logos
Add up to 5 logos
Videos
Add up to 5 videos
Headlines
Add up to 5 headlines (maximum 30 characters)
Long headlines
Add up to 5 long headlines (maximum 90 characters)
Descriptions
Add one short description with maximum 60 characters and up to 4 descriptions with maximum 90 characters each
Call-to-action
You can choose from various layouts as well as enter the name of your business or brand
Ad URL options
You can add the pathway for your display URL as well as choose a different final URL for mobile
More information and success stories
https://blog.google/products/ads-commerce/performance-max/
https://support.google.com/google-ads/answer/10724817
https://support.google.com/google-ads/answer/11189316
https://support.google.com/google-ads/answer/6095947
https://support.google.com/google-ads/answer/10256472
https://www.thinkwithgoogle.com/feature/how-automation-works/
https://developers.google.com/google-ads/api/docs/performance-max/assets
If you want to know more about Google Ads audits, then visit the following link
Google Ads Audit guide & free [Notion & Google Sheets] template
Top posts in Google Ads
How to audit Google Ads campaigns