Check it before you send

Load your assets in and we’ll render them in the real unit, flag anything production would reject, and tell you what’s still missing for Cover. Nothing uploads; everything stays in your browser.

This is our example creative. Replace the copy and assets with yours, and the verdict and the preview both update as you go.

The standard unit

ads via CarbonYour time is valuable. Use it to focus on your app, and let us handle login and much more.ads via Carbon

Runs on every placement in the network. With no 260×200 supplied it falls back to your 500×500. Send the 4:3 crop and this pane is what changes.

Carbon Cover

Hover the unit to see the expanded state.

Your creative

Nothing uploads; files stay in your browser.

JPG, PNG, or WEBP up to 300 KB. Avoid logos and text, which the unit renders separately.

The 4:3 crop, up to 300 KB. Sent alongside the square, and the standard unit renders this one.

Transparent PNG up to 300 KB.

Always visible, even without interaction. Make it work on its own.

100 characters including spaces. One clear sentence with the call to action at the end. Plenty of readers see nothing else.

One concise action, matched to your primary onsite goal.

Shown when someone shares the ad. Left blank, we use the name of the company buying the ads.

The whole unit clicks through here. Send one per creative, each with its own UTMs, so you can tell the variations apart.

No light colours: the text on top is white. Left blank, we pick a shade from your image with enough contrast.

Once a campaign is booked

Your account manager sends a collection link where assets are submitted, reviewed and approved. This tester is the pre-campaign check. That link is where the final creative goes. Talk to us about a campaign if you don’t have one yet.

Still deciding what to make? The creative brief shows what a good one looks like, with real ads from the developer network.