MiniMax H3 vs. Grok Imagine: We Tested Them With Real Ads

With the latest release of MiniMax H3, social media filled up with posts calling it even better than Seedance. At SeeD EM, we wanted to answer a more concrete question: how good is it compared with Grok Imagine, the model we use in some projects and with some clients? We put it to the test with real ads, in two rounds.

In short:

• For images, H3 is faster, but Grok makes better ads. H3 generates in about half the time and its photography is excellent, but Grok highlights the offer better and makes fewer spelling mistakes.
• For video, H3 won. With a well-written prompt, H3 Max animated our creatives three times faster than Grok, at half the price and without distorting the text.
• How you prompt it changes everything. With a prompt written for another model, H3 fails; with one written in its own format, it performs very well.

Why We Tested It Ourselves

Almost every post about H3 shows demos picked by whoever publishes them, with prompts designed to show the model at its best. That is fine for building excitement, but it says nothing about how the model handles everyday work: a restaurant that needs its weekend menu, or a store that wants to announce a discount.

At SeeD EM, we use generative AI to produce ad creatives, and in some projects we already work with Grok Imagine, from xAI. So the question was practical: is H3 worth it compared with what we already use?

How We Tested It

We used real requests from our team: restaurants, a spa, an ice cream shop, a specialty coffee brand, fashion, tourism and solar energy. Both models received exactly the same input: the same brief, the same product photos and, for video, the same starting image. We measured how long each creative took and how much it cost, and we reviewed spelling, product accuracy and how well the offer stood out, one by one.

We ran two rounds. In the first, we used each model out of the box. In the second, we gave H3 its best shot by following MiniMax’s official guide to the letter. In total, we reviewed more than 100 images and about 15 videos.⁶

Images: H3 Is Faster, Grok Makes Better Ads

On speed and price, H3 delivers what it promises: it takes less than half the time, and its times barely vary. That said, if you also rewrite the brief for H3, as we recommend below, that time advantage shrinks. Its photography is understated and very believable, and when you give it the logo and the product photo, it reproduces them as well as Grok.

Grok wins where it matters most in an ad. It builds creatives that sell, with the price front and center, and it writes better. H3 leans minimalist and leaves the offer in a small label, as you can see with these discounted solar panels:

There were also spelling mistakes, especially in small text. Neither model is perfect, but H3 made more errors:

The lesson is the same one we apply to any AI-generated content: a person must review every creative before it is published.

The Trick: H3 Needs You to Describe the Image, Not Give It Orders

In the first round, we sent H3 the same brief we sent Grok: a list of instructions that included phrases such as “No incluir nombre de marca ni logo” (“Do not include brand name or logo”). H3 did something unexpected: it wrote those phrases inside the image, as if they were part of the ad.

The solution is in MiniMax’s own guide: H3 performs better when you describe the finished image than when you tell it what to do.⁴ Compare these two excerpts:

How we prompted Grok (excerpt):

Do NOT show it displayed on a physical billboard, screen, or any mockup […] No incluir nombre de marca ni logo […]
(1) a large bold headline reading exactly 'Relájate y renueva';

What works for H3 (excerpt):

Centered in that open upper space is a large bold headline in a delicate serif typeface reading 'Relájate y renueva', sized as the dominant text element […] Below the headline, smaller and visually secondary, is a highlighted callout badge […] containing a small minimalist clock icon beside the text 'Lunes a viernes, 4:00 p.m. – 7:00 p.m.'

With that change, the product errors also disappeared. We asked for an artisanal coconut ice cream: with the original prompt, H3 served a strawberry parfait; with a well-written description, it got it right.

If you are going to try H3, these five tips will save you time:

• Describe what the finished ad looks like, in English, and keep only the on-image text in its original language.
• Put that exact text in quotation marks and say where it goes and how large it is.
• Describe the product by how it looks, not by what it is called: “red beans in a thick broth, with pork crackling” works better than “frijoles paisas”.
• Avoid negatives. The only useful one is stating that the image has no text.
• Generate two or three versions of each creative and keep the best one.

Turning what the business needs into precise instructions for each model is work worth automating, but without losing control. It is the same principle behind SeedPilot, our AI agent for creating and optimizing content in Drupal: AI does the heavy lifting, and a person approves every change.

Video: This Is Where H3 Surprised Us

Animating an ad has a well-known problem: video models redraw every frame and tend to distort letters, prices and logos. With Grok, we solve this with an extra step that places the original text back on top of the video.

In the first round, H3 was not convincing. Its standard version took about 4 minutes per clip, and the fast one, Highspeed, erased all the text from one of the creatives. But when we rewrote the brief in MiniMax’s official video format⁴ and tried its H3 Max variant, the result changed completely:

The creatives in this test belong to clients, so we are not showing them. To let you see the result, we used the same method to animate a generic creative: the glow and the reflection move, the text does not.

Three creatives are too few for a definitive conclusion, which is why we are going to expand the test. But the difference from the first round is too large to be a coincidence.

Watch Out: “H3” Is Not a Single Model

Much of the confusion on social media comes from the fact that several models, released at different times, share the name “H3”:

• MiniMax H3, the video model, was released on July 31, 2026.²
• H3-Image, the image model we tested, was released on November 10. Any opinion about “H3” images from before that date is about a different model.¹
• The video variants came later: H3 Max between late August and early September, and Highspeed and Lite in late October, according to archived versions of MiniMax’s pricing page.³⁵
• The open-source version only goes up to 768p, does not include prompt enhancement, and its license excludes the United States, the European Union, the United Kingdom and South Korea.

Before drawing conclusions from a demo, it is worth asking which H3 it is talking about.

Our Verdict

H3 is a serious model and not a social media gimmick, but it is not better than Grok at everything. This is what we would recommend today:

With either model, a person has to review every creative before it is published. And if you are going to use H3, write to it in its own format: it is the difference between a bad result and a very good one.

What This Means for Your Company

Generative AI models change every few weeks, and the one that is trending today may not be the best for your case. Three ideas we take away from this test:

• Test with your own cases. A viral demo will not tell you how the model will behave with your catalog, your brand and your language.
• Design the workflow, not just the model choice. How the brief is written, who reviews it and who approves it matter as much as the tool. We explain this in smart editorial workflows with Drupal and AI.
• Stay in control. Switching AI providers should be a technical decision, not a new project. That is why your site and your content should not depend on a single model.

At SeeD EM, we have spent 18 years building digital platforms, and today we help companies integrate AI into their content operations with sound judgment and governance. If your team wants to do this without depending on the model of the moment, you may be interested in Drupal as a Service, our managed platform with built-in AI, or Website as a Service, designed for small and medium-sized businesses that need a website, content and SEO (Search Engine Optimization) without building their own team. You can also see what we have done in our success stories.

Would you like the full technical report, with all the figures and the prompts we used? Write to us and we will share it with you. We look forward to hearing from you.

Sources

1. MiniMax H3-Image: official announcement ↩
2. MiniMax H3: official announcement ↩
3. MiniMax model release notes ↩
4. Official prompt-writing guide for H3-Image and for H3 video ↩
5. MiniMax pricing ↩
6. Time, cost and quality measurements: SeeD EM’s own tests, November 11, 2026 ↩

If you are interested in how AI is changing the work of marketing teams, we also recommend the new role of the CMO: technology, data and AI.

Published by SeeD EM · November 2026.