Nano Banana Web Grounding: References Before Prompts
MidassAI Team · August 8, 2026 · 6 min read
A date in an image prompt describes what you want; it does not prove that an image model retrieved current evidence. For a real building, changing storefront, or seasonal campaign, the reliable workflow is to identify the subject, inspect the available references, and then review the generated picture against them. Treat visual search as an input to the work, not a guarantee of factual accuracy.
Google's Nano Banana 2 announcement describes Gemini 3.1 Flash Image using real-world knowledge and information and images from web search. That announcement dates to February 26, 2026. This tutorial was revised on October 14, after checking it alongside the Nano Banana 2.1 model card, published October 6. The newer model is based on Gemini 3.6 Flash; the names are not interchangeable API identifiers.
Separate the subject from the time requirement
Start with the part of the picture that must be recognizable. Name the building, object, or place precisely enough to distinguish it from similar subjects. Add the viewpoint and features that matter. A request for a city skyline leaves much more room for interpretation than a request focused on one named landmark from a specified side.
Keep three decisions separate
Next, decide whether the date is factual or artistic. “An autumn color palette” is an artistic instruction. “The entrance after its September renovation” is a claim about a real change. The second requires a dated source that shows what changed. Warm leaves and a calendar phrase cannot establish that the correct entrance was rendered.
Keep these requirements in separate notes. One note describes the subject and reference evidence. Another describes composition, lighting, material, and intended use. This makes it easier to see whether a disappointing result comes from the wrong reference or simply the wrong visual treatment.
Check what the selected product actually supports
Confirm the model and the image-generation or editing interface you are using. Search capabilities, reference inputs, and visible controls should be checked in that product's current instructions. Do not invent a universal “Live Context” switch or assume that a control described for one product exists in another.
A natural-language request to search first can express your intended process, but it cannot enable an unavailable tool. Likewise, adding a date does not force a particular retrieval window. If the product exposes sources or search results, inspect them. If it does not provide enough evidence to verify the reference, obtain an appropriate source yourself and supply it through a supported reference-image workflow.
Nano Banana 2.1's model card still lists limitations in factuality, spatial reasoning, and some text rendering. A newer version therefore does not remove the need for review. Use the exact model identifier documented for your selected interface when working with an API; do not derive one from the marketing name.
Build a small reference set
Choose references for specific reasons. A front view may establish the entrance and window arrangement, while a side view explains the roofline. Prefer a small set that resolves those questions over many pictures with different dates, viewpoints, and unknown origins. More images can create more ambiguity when they disagree.
Record the page where each reference came from and, where available, the date of the photograph rather than only the date of the webpage. A recently updated travel page can still contain an old picture. For a time-sensitive change, look for evidence that actually shows the change and keep the uncertainty visible if you cannot find it.
Write a short inventory of features to preserve: the number of prominent roof sections, the entrance position, or the relationship between a courtyard and the main facade. These are proposed review criteria, not a promise that the model will reproduce every detail. For people or products, the reference-editing guide covers preservation requirements in more detail.
Write the visual brief after checking the references
For an illustrative travel card, you might use the following original prompt. It assumes that you have supplied suitable reference images and checked their dates:
Create a wide editorial illustration of the building in the supplied references, viewed from the front courtyard. Preserve the main roof shapes, entrance position, and visible window arrangement. Use a restrained geometric style, warm stone colors, and a quiet blue sky. Leave clear space above the roofline for a separate headline. Do not add signs, logos, temporary installations, or people that are absent from the references.
If a recent renovation matters, add a separate instruction identifying the dated reference that shows it. Do not simply append “latest version” and hope the model resolves conflicting sources. If the available references do not establish the current state, narrow the brief to a clearly labeled conceptual illustration or choose a different subject.
Set dimensions and other output options through the controls or parameters documented for your tool. Do not paste Midjourney flags such as --ar or --quality into a Nano Banana workflow as though they were verified API settings. You can describe the desired composition in ordinary language while configuring the actual output separately.
Review identity before style
Compare the candidate with the selected references at a useful viewing size. Start with the features that establish identity, then check relationships: which structure sits in front, which side contains the entrance, and whether a repeated window pattern belongs to the correct wall. A convincing overall silhouette can hide a wrong detail.
Next, inspect features the model may have added. A small plaque, new doorway, or extra roof section can look plausible while changing the subject. Keep an explicit list of additions that should be removed. Do not let pleasing color or texture compensate for a factual requirement that failed.
Only after that review should you judge style, contrast, and the destination crop. A good full-width image may lose its defining entrance in a small card. Check both sizes before accepting the file. If exact wording is required, place and proofread the final text in your layout tool rather than relying on an attractive but unchecked sign inside the image.
Revise one problem at a time
When most of the frame is usable, name the defect and the features to preserve in the next edit. For example, request correction of the roofline against one supplied reference while keeping the approved viewpoint and palette. Save the accepted version separately so that an unsuccessful edit does not become the new baseline.
If the subject remains wrong, revisit the source set. Contradictory photographs, an ambiguous place name, or missing views are input problems. Repeating stronger adjectives will not resolve them. Use a clearer reference, simplify the scene, or select a presentation that does not imply unavailable precision.
Save the final image together with the chosen model, prompt and references. Include any accuracy questions that remain open so the next editor knows what still needs checking. When a building, product or sign changes, update the reference set before revising the image; stronger wording cannot replace newer evidence.