ChatGPT Ads Specs: Image Sizes, Character Limits, and Creative Rules

Every ChatGPT ad is one small card: a square image of at least 256×256, a logo that renders at 32×32, a title capped at 50 characters, a description capped at 100, and exactly one destination URL. This post is the spec sheet - and the creative rules that matter when your entire ad is about half a tweet.

The complete spec sheet

Here is every creative requirement in the OpenAI Ads Manager, in one table.

That is the entire format. There are no asset variants for the system to rotate; what you upload is what renders. We cover where the unit appears in our full anatomy post, and the account setup sequence in our Ads Manager walkthrough.

Image specs: upload big, design for small

The floor is 256×256 (OpenAI Ads Manager docs, 2026). Upload well above it - the platform downscales cleanly from a high-resolution square, and an upload at the bare minimum leaves you nothing in reserve if OpenAI renders the unit larger on some surfaces later.

The harder discipline is the opposite one: design for how small the image actually renders. The card sits below a text answer on what is often a phone screen. In practice that means:

One subject, filling the frame. A single product on a clean background beats a lifestyle scene every time at this size. If a viewer cannot tell what the product is at thumbnail scale, the image is decoration, not communication.

No text in the image. Small type becomes unreadable once the card renders at phone scale - and image text duplicating your title is one of the patterns we see get creative flagged in review. Your 150 characters of copy live in the title and description fields; let the image do the one job copy cannot.

High contrast against both themes. ChatGPT runs in light and dark mode. An image with a white background disappears into light mode's card edge; a near-black one does the same in dark mode. A defined product silhouette or a solid mid-tone background survives both.

If you are running product feed ads - the June 2026 format where ChatGPT auto-generates ads from an uploaded Google Shopping-format catalog, 100 SKU minimum (OpenAI Ads Manager docs; Digiday, June 2026) - the same logic applies to your feed images. Your catalog's primary image field is your creative. We cover the feed side in our feed requirements guide.

Character limits: 150 characters, one argument

Fifty characters of title. One hundred of description. Together that is about half a tweet, so the format punishes anything that tries to do two jobs.

Make the title the outcome, not the brand. Your advertiser name and logo already render on the card, so a brand-name title says what the unit says twice already. "Ships in 2 days, free returns" earns its 29 characters. "BrandCo - Quality You Can Trust" earns none of its 31.

Make the description the proof. One specific claim: a price, a concrete spec, a shipping promise, a named ingredient. Vague benefit copy ("elevate your routine") reads as filler at any length; at 100 characters it is fatal.

Match the buyer moment, not the category. There are no keywords in this system. Matching is conversational - the current conversation topic, past chats, past ad interactions - and you steer it with 5-15 context hints per ad group, each a 1-2 sentence description of a buyer moment (OpenAI Ads Manager docs, 2026). Your title should read as the natural next line of the conversation your hints describe. If your hint targets "someone comparing running shoes for wide feet," a title about wide-fit sizing will outperform a generic brand line. We go deep on hint-writing in our context hints guide.

The favicon problem: your logo at 32×32

Thirty-two pixels square is favicon territory, and most brand logos were never designed for it. Full wordmarks collapse into a gray smear; detailed marks lose every distinguishing feature.

Before launch, export your logo at actual 32×32 and look at it on a phone. If you cannot identify the brand, neither can anyone else - and because the logo is part of the sponsor identification on a labeled unit, an unreadable one is a rejection pattern, not just a performance problem. If your primary mark fails the test, upload the simplified icon version - the same asset you would use as an app icon or favicon.

Common rejection reasons

Persona verification, business details, tax ID, and an account logo are all required before an account serves at all. Past that gate, these are the creative-level patterns that get ads rejected or sent back in review:

Destination domain mismatch. The single most common one. Your destination URL must belong to the business you verified. Sending clicks to a link shortener, an unrelated microsite, or a marketplace listing under a different seller name reads as misrepresentation. Use your verified domain; use UTM parameters, not redirects, for tracking - your conversion measurement runs through the OpenAI pixel and Conversions API regardless.

Claims the landing page does not support. A "50% off" title pointing at a full-price page is a straightforward reject. The title is a promise; the URL is where it gets checked.

Illegible creative. Logos that are noise at 32×32, images stuffed with baked-in text, low-resolution uploads stretched to the minimum.

Category and policy restrictions. Standard ad-platform exclusions apply. If your vertical is restricted on Google and Meta, assume it needs review here too.

A reject is not a ban - fix the mismatch and resubmit. But every review cycle costs days of delivery in a system that already ramps slowly during beta by design (OpenAI onboarding).

Where Tru Commerce fits

Getting the specs right earns you a well-formed ad. It does not earn you the recommendation. Every ChatGPT conversation has two layers: the organic answer, where ChatGPT names the products it actually recommends, and the labeled sponsored box below it. As our founder put it in The Hindu BusinessLine (Aug 28, 2026): "Brands cannot buy influence over ChatGPT's answers." Plus and Pro users never see the ad layer at all - for them, the earned recommendation is the only surface you have.

And the earned layer is where the economics live: ChatGPT-referred ecommerce traffic converts at 15.9% versus 1.76% for Google organic (Adobe, 2025), while the ad unit itself clicks through at roughly 0.9% industry-wide (eMarketer, 2026) - about 1.3% in our own US campaigns since July 2026 (our campaign data).

So before you spend a rupee or a dollar on the sponsored box, find out whether ChatGPT already recommends you organically. Our free Citation Rank scan shows where your brand stands across AI surfaces in 24 hours - no login, no credit card. Then use our ChatGPT Ads hub to decide whether the paid layer is worth adding on top, and our shopping teardown to understand how the organic layer actually picks products.