A small Polish online store needs a steady stream of visuals: category banners, seasonal promotions, social posts and product scenes. Free AI image generators can cover a large part of that work, and the choice grew after ChatGPT Images 2.5 launched on September 8, 2026 alongside Google's Nano Banana 2. But a tool that produces beautiful English posters may still break the Polish letters in a headline, and a free plan may not fit a shop that publishes daily. This guide is written for Polish e-commerce teams. It shows how to test tools with Polish text, where free plans stop being enough and which rules to check before images go on a shop or marketplace. Information is from public sources and correct on September 20, 2026.
Why Polish text is the real test
Most comparisons judge realism. For a Polish shop the first question is different: can the tool write "Promocja świąteczna" or "Darmowa dostawa od 199 zł" without corrupting the letters ą, ć, ę, ł, ń, ó, ś, ź and ż? Nano Banana 2 is documented by Google as rendering and translating text inside images, and ChatGPT Images 2.5 reports sharper handling of complex layouts. Ideogram built its name on readable typography. None of these promises guarantees clean Polish, so test it.
A ten-minute Polish-text test
- Choose a short headline with many diacritics, for example "Zażółć gęślą jaźń" as a stress test and "Wyprzedaż jesienna do -30%" as a real one.
- Ask for the same banner in each tool: flat background, one product, the headline in quotation marks.
- Zoom in and check every diacritic, the percentage sign and the price format.
- Count how many attempts each tool needed to get the text right.
- If text keeps failing, generate the image without text and add the headline in Canva or your design tool. This is often the most reliable workflow.
Which tools to shortlist
- Nano Banana 2 in the Gemini app. Strong on text, editing and keeping a product consistent across images. It supports up to five characters and 14 objects in one scene according to Google. Daily free limits apply and reviews quote between 20 and 100 images, so check your account.
- ChatGPT Images 2.5. Good at following multi-step edits. Its Sketch feature lets you draw a rough banner layout for the model to follow.
- Canva. Not the strongest generator, but it gives a daily allowance of AI images inside an editor with templates, which suits shop banners.
- Ideogram. Reportedly 10 slow credits a week on the free tier; useful for typography experiments.
Adobe Firefly reportedly gives 25 credits a month free of charge and may watermark output, so it fits occasional use rather than a daily shop schedule.
What a shop can realistically make for free
- Category and campaign banners without a photo shoot.
- Lifestyle backgrounds behind a real product photo, edited by instruction.
- Social posts and story backgrounds for Black Friday or Christmas.
- Concept images to brief a designer.
Where free plans struggle is volume and consistency. If you need dozens of on-brand images a week, a paid tier or API is more predictable. Google lists Nano Banana 2 at about $0.067 per 1K image on standard API pricing, with no free API tier, so a batch of 100 images is roughly $6.70 before retries.
Rules and platform checks for Poland
- Product accuracy. Do not present an AI image as a real photo of the product you sell. Misleading visuals can create consumer-protection problems and returns.
- Marketplaces. Marketplace listings often have their own image requirements, for example a plain background and no added text. Read the current rules of each marketplace before uploading generated images.
- AI labelling. EU rules on transparency for AI-generated content are being phased in, so check the current requirements that apply to your channel. Both OpenAI and Google embed provenance signals such as C2PA metadata and SynthID, but they do not replace your own labelling.
- Commercial use. Confirm on your plan that commercial use is allowed. Some free plans exclude it, and at least one popular tool is reported to make free images public.
A simple weekly routine
Monday: pick three promotions. Tuesday: generate backgrounds and banners without text. Wednesday: add Polish headlines in your editor and review every letter. Thursday: publish and record the prompt, tool, plan and date. Friday: compare click rates and keep the styles that work.
Related reading: our look at Google's AI ad formats, the AI SEO workflow and Seedance 2.0 for Polish online stores if you want to turn the same product into short video.
Seasonal prompts for the Polish retail calendar
Polish shops plan around a familiar calendar, and prompts can follow it. For Black Friday, ask for a dark, high-contrast background with an empty area for a discount label. For Christmas, ask for warm light, a wooden table and a wrapped gift next to the product. For Women's Day, ask for a soft pastel scene with flowers. For back-to-school, ask for a clean desk with a notebook and a backpack. In every case keep one main subject, leave clear space for text and add the headline in your editor so the Polish letters stay correct.
Common mistakes in Polish online shops
- Trusting the first result without zooming in on the diacritics.
- Putting the price and the discount percentage inside the generated image, where a mistake is hard to fix.
- Mixing styles in one category so that the shop looks inconsistent.
- Publishing a generated scene next to a product that looks different from the real item.
- Forgetting that a free plan may drop to a weaker model after the daily limit, which changes the style mid-campaign.
- Not recording which tool and plan produced which banner.
FAQ
Can free AI generators write Polish letters correctly? Sometimes. Test with a headline full of diacritics. If a tool fails, generate a picture without text and add the words in Canva.
Are free AI images allowed on marketplaces? Check each marketplace's current image rules. Many require realistic product photos on a plain background.
Do I need to label AI images in Poland? Rules are evolving under EU law and depend on the channel. Label realistic images of people or events to be safe.
When should a shop pay? When you need consistent daily output, no watermark or guaranteed commercial terms.
Summary
For a Polish online store, the best free AI image generator is the one that passes your Polish-text test and still leaves time for review. Shortlist two tools, add headlines yourself when needed and keep a record for every image. If you want a plan that connects visuals, content and search visibility, see our content optimization and SEO marketing services.
