Postmint Is Live: On-Brand Social Graphics From One Sentence

A sale starts Monday. You know exactly what you want to say about it. What you don’t have is the graphic, so you open Canva, hunt for a template, nudge the colors toward something close to your brand, and forty minutes later you have a post that looks like every other post made from that template.

That job comes back every week, and in a small company it lands on whoever also does the invoices. Postmint is my attempt to make it take two minutes. It went live in mid-July at postmint.de.

You set up a brand kit once: colors, a font, your logo. After that you describe the post the way you’d describe it to a colleague. “Summer sale, 20 percent off, ends Sunday.” Postmint writes the words that go on the image, builds the layout, and hands back a pixel-perfect PNG in your colors at the right size for wherever it’s going. Instagram post, story and carousel, plus LinkedIn. If you want the caption written too, it comes with the image.

Ten graphics a month are free, no card, so the fastest way to judge Postmint is to put one of your own posts through it.

Why it doesn’t look generated

My first prototype fed the brief straight to an image model. I made twenty images, looked at them, and would not have posted a single one. You know the look: half-empty canvas, a gray gradient doing nothing, a fake button painted on that leads nowhere, a price the model invented. Technically an image. Also obviously slop, and posting that costs a brand more than posting nothing does.

So I deleted it, and Postmint never generates pixels.

The model writes an HTML document instead. Every design starts from one of 24 hand-built templates, and a real headless browser renders the result. Then two passes look at it before you do.

The browser proves geometry. It walks the rendered DOM and reports five faults it can measure rather than guess: text extending past the canvas, text clipped by an ancestor that hides overflow, a box too small for its own text, text painted over by an opaque shape, text overlapping other text. Every fault comes back with an element reference attached, so the fix round knows what to touch.

A vision pass then looks at the actual screenshot and judges it against the brief, the reference style, and your brand’s color values. It catches what geometry has no opinion about: low contrast, a composition that’s mostly empty, a palette that drifted off your primary.

Both feed a revise step. The loop runs a couple of rounds before anything reaches you. If a render or a model call fails mid-loop, it falls back to the best version so far rather than handing you an error.

I got the next part wrong in my own copy for a week, so here’s the precise version. Your logo and any stock photos are substituted into the HTML deterministically. Color works differently: your palette goes in through the prompt, and the critique pass is what holds a design to it, sending a drifting palette back for another round. So color is enforced by review. Still a stronger claim than any raw image generator makes, and it has the advantage of being accurate.

Where it loses

Canva wins the moment you want control over the layout itself. Postmint gives you 24 layouts and no blank canvas, deliberately, because that constraint is most of what keeps the output looking designed. If you need one specific arrangement of specific elements, use a design tool.

Editing an existing design is the weaker path as well. An edit is a model-authored find-and-replace on the HTML, so asking it to recolor a finished design can leave the biggest element on the canvas behind. Generating fresh against the updated brand kit is more reliable than patching an old one. Fixing that properly is next on my list.

What it costs

Free is 10 graphics a month, no card. Starter is €19 net a month for 50, Pro €49 net for 150, both cheaper annually at €15 and €39 a month. Built in Germany, works in German and English.

Under the hood

Laravel 12 with Livewire 3 for the app, and a separate Node service that keeps a headless browser warm and screenshots composed templates into PNGs. Anthropic and OpenAI handle the copy and the vision critique, Cashier does billing, Resend does mail, and the whole thing runs in Docker on Dokploy. There’s more detail on the Postmint portfolio page.

Poke at the output before you sign up for anything: the template gallery is open, 24 examples, no account needed.

The launch itself went badly. I wrote that up separately, with the real numbers: I launched to crickets.