Nano Banana 2.5 AI Image Model Guide

TL;DR: Nano Banana 2.5 hasn't been announced by Google. It surfaced first as code references inside the Gemini desktop app, then again under the codename "Spicy Mayo" in Google's own Image Arena testing environment. No model card, no pricing, no release date. Nano Banana 2 , Nano Banana Pro and Nano Banana 2 Lite are both live and free to start on OpenArt right now, and Nano Banana 2.5 will land in the same Create Image tool once it ships.

What is Nano Banana 2.5?

Nano Banana 2.5 is the name attached to an unreleased update to Google's Nano Banana image-generation line. Nobody outside Google has used it officially, and Google hasn't confirmed it exists. What we have instead is a paper trail: researchers Bedros Pamboukian and Alexey Shabanov spotted references to "Nano Banana 2.5 Flash" inside code traces in the Gemini desktop app, reported by TestingCatalog on September 5, 2026. Pamboukian's original post on X put it simply: "there is another new model that caught the attention of my crystal ball. Nano Banana 2.5 Flash. Interesting." That's the entire extent of the first sighting, nothing about specs, pricing, or timing.

TestingCatalog has a track record worth noting here: it's the same outlet that caught Nano Banana 2's preview card before Google confirmed that model, which is most of the reason this particular leak is worth paying attention to at all.

What Google's Image Arena testing actually means

Image Arena is the internal environment Google uses to run unreleased models through blind, side-by-side comparisons before deciding what to ship. It's the same basic idea behind public model arenas like LMArena, except this one runs inside Google, with test builds that never get a public name until launch. A model showing up there doesn't mean it's finished. It means Google is far enough along to start measuring it against rivals.

That's the context for why a codename like "Spicy Mayo" surfacing here is worth more than a random leak. Getting into Image Arena is itself a signal of internal progress, even before anyone knows what the model will eventually be called in public.

Confirmed vs. unconfirmed, at a glance

The "Spicy Mayo" sighting

A few days later, on September 9, 2026, a second signal turned up: a build codenamed "Spicy Mayo" appeared in Google's Image Arena, the internal environment Google uses to test models against each other before release. The report traces back to Md Ismail Šojal, who described hands-on access to the build as "a significant jump but not meaningfully better than GPT-Image 2.5, especially when it comes to world knowledge." A second account, LuminaBench, corroborated the Arena sighting independently, though even LuminaBench characterized the link between Spicy Mayo and Nano Banana 2.5 as "a possibility rather than confirmed."

None of this confirms Spicy Mayo and Nano Banana 2.5 are the same build. Two accounts pointing at the same test build is a stronger signal than one, but it's still a reasonable connection, not a confirmed one.

Worth being direct about the evidence quality here: this is a handful of social posts from a handful of accounts, not a benchmark, not a model card, and not a Google announcement. Enough to justify watching this space. Not enough to publish as a spec sheet.

How the early reports stack it up against GPT-Image 2.5

The only external comparison anyone has actually made is against GPT-Image 2.5, not against Midjourney or another Google model. That itself says something: Md Ismail Šojal, who had hands-on access to the Spicy Mayo build, treated GPT-Image 2.5 as the relevant bar to clear, not older competitors.

Their verdict, again in their own words: "a significant jump but not meaningfully better than GPT-Image 2.5, especially when it comes to world knowledge." Read that carefully. It isn't a claim that Nano Banana 2.5 loses to GPT-Image 2.5 outright. It's a claim that on one specific axis, world knowledge (roughly, how well a model understands and renders real-world facts, objects, and relationships inside an image), the gap hasn't closed. Everything else about the comparison, quality, speed, editing behavior, is unstated.

One account's read on a pre-release build, even independently corroborated by a second account, is not a benchmark. Treat it as the closest thing to a performance signal that exists right now, and nothing more than that.

What this would mean if the pattern holds

Nano Banana 2.5's naming puts it after Nano Banana 2 and Nano Banana 2 Lite, both live today. Google's higher-end tier. Google's own naming for the leaked reference, "Nano Banana 2.5 Flash," keeps it in the Flash family rather than the Pro one, which suggests this is a refinement of Nano Banana 2, not a jump to Pro-level positioning. If it follows the pattern of the last few Nano Banana releases, expect it to match Nano Banana 2's resolution and reference-image handling at minimum, with the reliability fixes users have been asking for layered on top: steadier output across long generation batches, more accurate reference-image matching, and fewer ordinary edits getting caught by content moderation.

All of that is a reasonable expectation based on the pattern so far, not a confirmed roadmap.

Where you can actually access it

There is no public entry point to Nano Banana 2.5 today. Here's what's confirmed about access, and what isn't:

What we still don't know

• Whether "Spicy Mayo" and "Nano Banana 2.5" are actually the same build, or two different things surfacing at the same time by coincidence
• The actual model ID or underlying architecture
• Real output resolution, aspect ratio options, and reference-image limits
• Real pricing, at any tier
• A real release date (the October 10, 2026 date circulating online is one rumor site's own placeholder guess, not Google's)
• Whether it replaces Nano Banana 2 outright or sits alongside it, the way Nano Banana 2 Lite sits alongside Nano Banana 2
• Whether the performance gap against GPT-Image 2.5 mentioned above holds up outside one person's early access, or changes before launch

Where things stand right now

Both Nano Banana 2 and Nano Banana Pro are live on OpenArt today, free to start, no credit card needed. If Nano Banana 2.5 follows the same release pattern as the rest of this model line, it'll show up in the same Create Image tool, same account, one click to switch over once it's available. There's no Nano Banana 2.5 page on OpenArt yet, since there's no released model to put on one, but this article will get an update the moment there's real news to report.

Frequently Asked Questions

Is Nano Banana 2.5 real?
It's not confirmed by Google. What's real is the evidence trail: code references inside the Gemini desktop app, reported by TestingCatalog on September 5, 2026, and a follow-up sighting of a "Spicy Mayo" build in Google's internal Image Arena. That's a credible signal, not an announcement.

When is Nano Banana 2.5 coming out?
Unconfirmed. A rumor-tracking site has published October 10, 2026, but the site itself labels that its own placeholder guess, not information from Google.

How much will Nano Banana 2.5 cost?
Also unconfirmed. The one public estimate out there, $0.03 to $0.07 per 1K images, is a single blog's speculation, not an official number from Google.

What's the difference between Nano Banana 2.5 and Nano Banana 2?
Nobody's confirmed the spec sheet yet. The naming (Nano Banana 2.5 Flash) keeps it in the Flash family rather than jumping to the Pro tier, which points to a refinement of Nano Banana 2 rather than a bigger leap. Treat any performance claims you see right now as unverified.

Is "Spicy Mayo" the same model as Nano Banana 2.5?
Probably related, not confirmed identical. The timing and the internal-testing context line up, but no one outside Google has confirmed the two names refer to the same build.

Can I use Nano Banana 2.5 on OpenArt right now?
Not yet, because it hasn't shipped. Nano Banana 2 and Nano Banana Pro are both live and free to start today, and Nano Banana 2.5 will land in the same Create Image tool the moment Google ships it.

Is the original Nano Banana (Gemini 2.5 Flash Image) still around?
Not for much longer. Google's own deprecation schedule lists gemini-2.5-flash-image for shutdown on October 2, 2026, with Nano Banana 2 named as the official replacement, not Nano Banana 2.5. That's a confirmed, dated fact from Google, separate from anything unconfirmed about 2.5 in this article. If you're still building on the original model, Nano Banana 2 and Nano Banana Pro are already live and free to start on OpenArt.