Preparing and Trafficking a Banner Set

From a 300×250 master to a live tag in six steps, with the rejection that waits at each one.

Step one: build the 300×250 medium rectangle first. It is the most widely accepted unit and the smallest common layout, so a design that works here can be adapted up; a design built for a billboard rarely survives being shrunk.

Step two: resize to the full set — 728×90, 160×600, 300×600, 970×250 and 320×50. Each size gets its own layout pass, because a direct stretch produces the most common rejection at this stage: a distorted or wrong-dimension export that does not match the slot.

Step three: export at 2× for high-DPI screens — the 300×250 ships as a 600×500 pixel file, and so on across the set. Step four: weigh every file. Static images must come in under the common ~150 KB cap and HTML5 units inside the 1-5 MB band; an overweight file is rejected at upload.

Step five: test the tag against the load budget — the creative must finish loading in under 2 seconds on a typical phone connection, a check that heavy HTML5 units fail even when they pass the weight cap. Step six: confirm viewability, verifying the placement can hold 50% of the creative's pixels on screen for 1 continuous second.

Once the set is live, the numbers it is judged by — viewability rate, CTR and the conversion windows — are defined on CTR, Viewability and Conversion Windows (/campaign-metrics). The size-by-size slot map is on Standard Display Ad Sizes (/display-ad-sizes).

• 1. Build the 300×250 master
• 2. Resize to the full six-unit set, one layout pass per size
• 3. Export every file at 2× for high-DPI screens
• 4. Weigh each file: ~150 KB static cap, 1-5 MB HTML5 band
• 5. Load-test the tag: under 2 seconds on a typical phone connection
• 6. Confirm viewability: 50% of pixels, 1 continuous second

Further reading

• Standard Display Ad Sizes
• CTR, Viewability and Conversion Windows