In-Market Display Campaign Specifications
Learn Cars.com In-Market Display ad specs, file requirements, animation rules, and click-through guidelines to ensure your dealership creatives comply.
General guidelines
Ads must have clearly defined borders. Creatives with white or light backgrounds must have a dark border.
Advertiser must be a dealership and must be clearly identified using a dealer logo and/or dealer name.
The dealership represented must be consistent with the enrolled dealer ID. Dealer groups may be advertised if the enrolled dealer is a member of the group.
Creative may not mimic or reference Cars.com editorial and/or advertising content
Creative may not refer to any unassociated dealerships
All dealer-submitted creative is subject to Cars.com approval
Creative formats and sizes
Supported display ad sizes vary by placement. Refer to the table below when building creative.
| On-site | Off-Site |
|---|---|
| 970×250 px | 728×90 px |
| 728×90 px | 728×90 px |
| 320×50 px | 320×50 px |
| 300×600 px | 300×600 px |
| 300×250 px | 300×250 px |
Accepted file types
On-site & Off-site: JPG, GIF, PNG, or HTML5
- HTML5 files must be secured with an HTTPS connection
- 3rd-party tags from approved vendors accepted.
Max file size limits for static assets
| Max File Size (On-Site) | Max File Size (Off-Site) |
|---|---|
| 728×90, 970×250, 300×600, 300×250
40 KB | 728×90, 970×250, 300×600, 300×250
40 KB |
| 320×50 50 KB | 320×50 50 KB |
Max initial file load size (HTML5, on-site only)
| Ad Sizes | Max Load Size |
|---|---|
| 728×90, 970×250, 300×600, 300×250 | 200 KB |
| 320×50 | 300 KB |
Animation guidelines
Animation is permitted only where specified
Maximum animation length: 15 seconds
Maximum loops/rotations: 3
Heavy file sizes negatively impact ad quality; optimize graphics and copy accordingly
Advertising content rules
Restricted content
Creative may not contain copyrighted logos, including the Cars.com logo, or imagery without proper authorization.
Sweepstakes or giveaway offers must include a disclaimer or “See dealer for details”
Creative may not contain graphic, obscene, or controversial material
Click-through link requirements
The entire banner must be defined as a clickable area
One click-through destination per banner
Click URLs must direct to a site consistent with the advertised products and the enrolled dealer ID
Ads may not link to a Cars.com competitor
Shortened URLs may be decoded to ensure publisher compatibility
Third-party tag rules
Non-compliant creative may be rejected or deactivated until required changes are made
4th-party ad tracking is not permitted
Click-through links must be encoded in the HTML or JS file
Cars.com is not responsible for regulating co-op eligibility or OEM marketing compliance
All submitted tags must be tested by Ad Operations on initial load (testing requires 7–10 days)
HTML best practices
All HTML5 creatives must follow a secure HTTPS protocol
HTML5 ads must follow W3C/WHATWG standards and include <!DOCTYPE html>, <html>, and <body> tags
Provide inline CSS and use HTML to deliver initial display resources where possible
Build creatives with a clearly defined border and contain ads within an iframe when possible
Load interactive elements as deferred or secondary sub-loads and avoid unnecessary downloads
Defer heavy file weights until user interaction
Do not use 4th-party or embedded click-counting code
File weight & performance notes
Initial file load includes all assets required for the first visual display
Minimize server calls; use sprite sheets and approved shared libraries when possible
File weights are calculated after gzip compression
Shared libraries must be publisher-approved to be exempt from file-weight limits
Ads should be compressed prior to serving; gzip is the recommended format
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