Bring your own key. Generate a bunch. Keep the best.
A Nano Banana image generator that runs on your own Google key.
Generate images in different styles, compare them side by side, and keep the ones you like.
Open BYOBanana 🔑 We never see your key
We don't do accounts or subscriptions. Just use your Google AI Studio key. Google API rates apply.
Bring your own key. Pick your best image. See what you spent.
BYOBanana has no servers. Everything runs in your browser, so we can't see what you make or what you spend. Google bills your key and reports the usage. BYOBanana just shows you the number.
The cost estimate updates before generation. Each requested variant calls Google's Gemini API through your key.
A bunch of options. One clear winner.
Chat windows are great at making one image at a time. BYOBanana makes a bunch at once, in different styles, and helps you pick the one you like.
Run one subject through up to three art style recipes. Generate one to eight variants per recipe. The results arrive in a contact sheet where the prompt, palette, and settings stay visible while you compare candidates.
- Compare every candidate in one grid.
- Inspect an image without losing the batch.
- Mark one candidate as primary.
- Select several candidates for export.
- Download one image on its own, or a ZIP with all your keepers.
Hold the art direction steady
The subject should change because you asked it to, not because you forgot which style words worked last time.
BYOBanana bundles repeatable prompt recipes for pastel illustration, hard-edge screenprint, pixel art, oil realism, ornamental miniature art, and project icons. Choose up to three recipes for the same brief, then apply one of seven fixed color palettes across the run.
Recipes are prompt contracts, not trained style models. They make the direction repeatable, but results will still vary.
- Compare several styles against the same subject.
- Keep the palette fixed while composition changes.
- Add reference images when text alone is not enough.
- Use Custom mode when you want full prompt control.
Explore the art style recipes and palettes
Airy pastel
Ornamental miniature
Tenebrist oil
Images and round project icons
Choose a standard image for editorial art, presentations, concepts, backgrounds, or site assets. Choose the project-icon family when you need a compact square composition that survives a circular crop.
For project icons, BYOBanana can turn a square generated image into a 384 by 384 PNG with transparent corners. The source image is clipped to a full-bleed circle.
This is raster icon output. It is not an editable SVG, vector logo, brand kit, or trademark review.
Make images, not accounts
BYOBanana has no backend, no server, no proxies. You use your own Google AI Studio key, and your browser talks directly to Google's Gemini API.
What that means:
- No account to make. No credits to buy.
- Google processes the prompt, reference images, and generated output.
- Google bills API use through the project attached to your key.
- BYOBanana saves your history in your browser, and nowhere else. Clear it and it's gone for good.
- Your key stays in this browser's memory. Turn on Remember and it's saved on this device only, as plain text, so skip that on shared computers.
Browser-based does not mean offline or fully private. Review the data flow before using sensitive material.
How it works
1. Add a Google AI Studio key
Open the key panel, paste your key, and validate it against Google's model list. Remembering the key is optional and off by default.
2. Set up a comparison run
Describe the subject. Choose images or a round project icon, one to three recipes, a color palette, optional references, model settings, and the number of variants.
3. Review cost, generate, and compare
Check the estimate before generation. Watch candidates fill the contact sheet, inspect the strongest options, and select the files you want.
4. Export the keepers
Download selected outputs as a ZIP. The bundle includes a text manifest with the model settings, rendered prompts, recipes, palette, and file hashes used for that run.
Frequently asked questions
What is Nano Banana?
Nano Banana is Google's name for the native image generation models in the Gemini API. BYOBanana is an independent browser interface for selected Gemini image models. It is not affiliated with or endorsed by Google.
Is BYOBanana free?
BYOBanana does not charge a subscription or sell image credits. Image generation uses your Google API key, and Google API charges may apply. BYOBanana shows an estimated run cost before generation.
Do I need an account?
You do not need a BYOBanana account. You do need a Google account, a Google AI Studio API key, and access to a supported Gemini image model.
Is BYOBanana a private AI image generator?
It has a limited privacy advantage: prompts, images, and the key are not routed through a BYOBanana application server. They are sent directly from your browser to Google, and Google processes them under the terms for your API tier. Sessions and images are also stored locally in your browser. It is not offline or fully private.
Where is my API key stored?
The key stays in browser memory unless you turn on Remember. Remember stores it as plaintext in localStorage on this device. Any script running on the same site origin could potentially read it, so do not remember a key on a shared device.
Can it create image variations from a reference image?
You can add reference images to a run and generate several candidates from the same brief. BYOBanana also supports prompt-first batches where every candidate starts from the same subject, style recipe, and palette.
Does it make logos?
BYOBanana can explore raster visual concepts and export round project icons. It does not currently create editable vector logos, typography systems, brand kits, or trademark-ready files.
Are generated images watermarked?
Google states that images generated by its current Nano Banana models include SynthID. BYOBanana does not remove or bypass it.
Generate a bunch. Keep the best.
Use your own Google key to create, compare, and export Nano Banana image variations.
Google AI Studio key required. Google API charges apply.