Diwali Poster AI Generator Free: Make a Shop Offer Poster in 10 Minutes

The easiest free Diwali poster AI generator for most shop owners is the Gemini app, which makes and edits images free with its Nano Banana 2 model. Adobe Firefly also gives free daily generations. Write a detailed prompt with your offer text in quotes, ask for a 1:1 or 9:16 size, then check spelling before posting.

Diwali falls on Sunday, 8 November 2026, with Dhanteras on Friday, 6 November (Drik Panchang, New Delhi dates; they can differ by city). That gives you a few days to get offer posters out on WhatsApp, Instagram and your shop counter. This guide shows how to do it free, with six complete prompts you can copy, and the checks that stop an AI spelling mistake from reaching your customers.

All tool details were checked on 2 November 2026. If you also want Reels, our Gemini video prompts for Reels guide has ten full video prompts.

Which free AI tool to use

Two notes. Google's own pages disagree on free download size: the help page says 1K without a plan and 2K with one, while the overview lists 2K for the free model. Check the download option you see. And Gemini's image page lists 18+ as an age rule, so use an adult's account.

The poster prompt formula

Google's image prompt guide breaks a prompt into five parts: style, subject, setting, action and composition. For text, it says to "enclose your desired words in quotes" and describe the typography. Google's tips post adds: "Clearly state what text should appear and how it should look", and suggests naming the format, such as "A 9:16 vertical poster".

For a shop poster, that becomes:

1. Size: 1:1 for WhatsApp and feed posts, 9:16 for Status and Stories.
1. Style: festive, clean, premium or playful.
1. Main visual: your product with diyas, marigolds, rangoli or lanterns.
1. Offer text in quotes: exactly as it should appear.
1. Typography and layout: where the text sits and how big it is.
1. Space for details: shop name, phone number and dates.

6 full copy-paste Diwali poster prompts

Replace everything in [brackets]. Keep the text short; long text is where AI makes spelling mistakes.

1. Sweet shop offer poster (1:1)

Create a 1:1 square festive poster for an Indian sweet shop for Diwali.
STYLE: Premium, warm, realistic product photography with soft festive glow.
SUBJECT: A brass thali with neatly arranged [kaju katli, motichoor laddoo, soan papdi], marigold flowers around it, three lit clay diyas in front.
SETTING: A dark maroon background with soft golden bokeh lights.
COMPOSITION: Thali in the lower centre, top third left clear for text.
TEXT (exactly as written, spelled correctly):
- Top centre, large bold gold serif font: "Diwali Special Offer"
- Below it, white bold sans-serif: "Flat [15]% off on mithai boxes"
- Bottom strip, small white text: "[Shop name] | [area] | [phone number]"
Keep the text sharp and fully inside the image. No other words.

2. Dhanteras jewellery poster (9:16)

Create a 9:16 vertical poster for a jewellery shop's Dhanteras offer.
STYLE: Elegant luxury, deep emerald and gold, soft studio lighting.
SUBJECT: A gold necklace and a pair of jhumkas on a velvet stand, a small brass diya beside them.
SETTING: Dark emerald background with subtle gold rangoli pattern at the edges.
COMPOSITION: Jewellery in the middle, text at top and bottom.
TEXT (exactly as written):
- Top, gold serif: "Dhanteras Offer"
- Middle-bottom, white: "[0]% making charges on [category]"
- Bottom, small: "[Shop name] | 6 November | [phone]"
Make sure the jewellery looks realistic and the text has no spelling mistakes.

3. Kirana or general store poster in Hindi (1:1)

Create a 1:1 square Diwali offer poster for a neighbourhood grocery store in India.
STYLE: Bright, cheerful, clean flat illustration with festive colours.
SUBJECT: A shopping basket with oil, dry fruits, sweets box and diyas, surrounded by small marigold garlands.
SETTING: Light yellow background with a simple rangoli border.
COMPOSITION: Basket centre-right, text on the left side.
TEXT in Hindi (Devanagari), exactly as written:
- Large, bold: "दिवाली धमाका ऑफर"
- Below: "हर ₹[1000] की खरीद पर [gift]"
- Small, at bottom in English: "[Shop name], [area] | Call [number]"
Use clear Devanagari font. Do not change or add any words.

4. Clothing boutique poster (9:16)

Create a 9:16 vertical Diwali sale poster for a women's clothing boutique.
STYLE: Modern festive fashion poster, rich magenta and gold, soft glow.
SUBJECT: A mannequin wearing a [colour] embroidered [kurta set / saree], with hanging lanterns above.
SETTING: Boutique interior softly blurred, warm fairy lights.
COMPOSITION: Mannequin on the right, text on the left half.
TEXT (exactly as written):
- Top, elegant script: "Festive Collection"
- Middle, bold: "Up to [30]% off"
- Bottom: "[Boutique name] | Till [date]"
Keep the outfit realistic and modest. Text must be spelled exactly as given.

5. Salon or beauty parlour poster (1:1)

Create a 1:1 square Diwali offer poster for a beauty salon.
STYLE: Soft, glowing, premium beauty-brand look, peach and gold palette.
SUBJECT: Makeup brushes, a small mirror and a lit diya on a marble table, a few rose petals.
SETTING: Clean pastel background with soft bokeh lights.
COMPOSITION: Products at the bottom, text in the upper half.
TEXT (exactly as written):
- "Diwali Glow Package"
- "Facial + Hair Spa at Rs [999]"
- Small at bottom: "[Salon name] | Book: [number]"
No faces. Keep all text sharp and correctly spelled.

6. Electronics or mobile shop poster (9:16)

Create a 9:16 vertical Diwali offer poster for a mobile phone and electronics shop.
STYLE: Modern, high-contrast, tech poster with festive lights.
SUBJECT: A generic smartphone (no brand logo) standing upright, with small glowing diyas and string lights around it.
SETTING: Dark navy background with golden light streaks.
COMPOSITION: Phone in the centre, text at top and bottom.
TEXT (exactly as written):
- Top, bold white: "Diwali Mega Sale"
- Bottom, yellow: "Easy EMI | Exchange offers"
- Very bottom, small white: "[Shop name] | [area] | [number]"
Do not show any real brand logos.

How to make it in Gemini, step by step

1. Open the Gemini app and choose image creation.
1. Paste the full prompt and send.
1. If the text is wrong, reply with a short fix: "Keep everything the same. Change the top text to exactly: 'Diwali Special Offer'."
1. To use your own product photo, upload it and add: "Use my uploaded photo of the product. Keep the product exactly as it is and build the poster around it."
1. Download the image, then check it on your phone at the real size.

Before you post: a 5-point check

Google's tips page says: "Rendering small text, fine details, and producing accurate spellings may not work perfectly", and "Multilingual text generation may make grammar mistakes or miss specific cultural nuances." So check every poster:

1. Spelling: read every word, especially Hindi and prices. Fix by asking Gemini to change only that text, or add the text yourself in a free editor.
1. Offer accuracy: the discount, dates and phone number must match what you will actually honour.
1. No fake brand logos or products you do not sell.
1. Watermark: Gemini adds a visible watermark. Decide whether you are fine with it on a business poster.
1. Size: 1:1 for WhatsApp and feed posts, 9:16 for Status and Stories.

A day-by-day Diwali poster plan (3 to 11 November 2026)

One poster is not a campaign. Customers need to see your offer a few times before they act, so plan a small series. Dates below follow Drik Panchang's New Delhi calendar; check your local panchang.

Keep the same colours, fonts and layout across the series so people recognise your shop at a glance. A simple trick: once you like a poster, tell Gemini "Make the next poster in exactly the same style, colours and fonts, but change the text to..."

Sharing on WhatsApp the right way

Most shop posters travel on WhatsApp, so a few rules matter. WhatsApp's Business Messaging Policy says you may only contact people who gave you their number and "you have received opt-in permission from the recipient". It also says you "must respect all requests (either on or off WhatsApp) by a person to block, discontinue, or otherwise opt out", and warns: "Do not confuse, deceive, defraud, mislead, spam, or surprise people with your communications." The policy adds that blocks and reports can limit how many messages you are allowed to send.

In practice:

• Send posters to customers who have asked to hear from you, for example people who bought from you or saved your number.
• Add one line such as "Reply STOP if you don't want offers" and actually stop when someone asks.
• Post on Status for everyone else; it reaches your contacts without pushing messages into their chats.
• Keep the offer honest. If the poster says "till 8 November", honour it till 8 November.

Turn posters into more business

A poster gets attention; a system turns that into orders. Zero To AI's AI Revenue System covers AI images, video and ads for small businesses. On 1 November 2026 its course page listed it at ₹1,999, with 12 hours across 36 lessons, self-paced. For more ready prompts, see our AI video prompts you can copy and paste.

Sources

• Drik Panchang: Diwali 2026 puja calendar (New Delhi)
• Gemini: Image generation overview
• Gemini Apps Help: Create and edit images
• Google DeepMind: How to create effective image prompts
• Google blog: Prompting tips for Nano Banana Pro (20 November 2025)
• Google blog: Nano Banana editing tips (2 October 2025)
• Adobe Firefly plans
• WhatsApp Business Messaging Policy

Last verified: 2 November 2026. Free limits and features change; check the app before you plan a big batch.