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GPT Image 1.5 vs Nano Banana Pro: Full Benchmark Comparison

By VibeDex ResearchOriginally published: February 7, 2026Updated: 18 February 2026

TL;DR

GPT Image 1.5 leads overall by a hair (4.64 vs 4.62) and wins more individual prompts (73 vs 68, with 52 ties). But Nano Banana Pro wins three of four quality dimensions — visual fidelity (4.99 vs 4.90), physics (4.66 vs 4.34), and subject integrity (4.51 vs 4.44) — while instruction adherence is tied (4.63 each). At nearly identical pricing ($0.133 vs $0.138), the choice comes down to your use case, not your budget. Note: GPT couldn't generate 7 of our 200 prompts due to content policy restrictions.

Overall Scores

GPT Image 1.5 and Nano Banana Pro are the two highest-rated models in our 18-model benchmark, separated by just 0.023 points on 193 shared prompts. Both score above 4.6 — well ahead of the third-place model. GPT was unable to generate 7 of our 200 benchmark prompts due to content policy restrictions, so scores are compared only on the 193 prompts both models completed.

#ModelAvg ScoreCost/ImageTier
1GPT Image 1.54.64$0.133Premium
2Nano Banana Pro4.62$0.138Premium

Average weighted score across 193 shared prompts. NBP completed all 200 prompts; GPT refused 7.

Dimension-by-Dimension Breakdown

Nano Banana Pro wins three of four dimensions. The largest gap is physics & logic (4.66 vs 4.34), where NBP renders materials and physical interactions more accurately. NBP also leads on visual fidelity (4.99 vs 4.90) and subject integrity (4.51 vs 4.44). Instruction adherence is tied at 4.63. Despite losing three dimensions, GPT Image 1.5 wins more individual prompts overall.

DimensionGPT Image 1.5Nano Banana ProWinner
Visual Fidelity4.904.99Nano Banana Pro
Physics & Logic4.344.66Nano Banana Pro
Subject Integrity4.444.51Nano Banana Pro
Instruction Adherence4.634.63Tie

These averages tell part of the story — but within each dimension, specific use cases can diverge dramatically. See the examples below for where the gap is largest.

Where Model Choice Matters Most

They score within 0.01 of each other on average — but averages hide the extremes. On specific prompts, the gap can exceed 1.0 points. Below are six use cases where model choice makes the biggest difference, selected for the largest score gaps in our benchmark. Each example includes win rate context so you can judge whether the pattern holds broadly or is specific to the prompt shown.

Marketing & branding

GPT wins 3 of 6 marketing prompts, NBP wins 2, 1 tie

prompt-0146

“Hand-lettered illustration for a vintage-style travel poster advertising VISIT KYOTO in large decorative type at the top, rendered in a retro 1950s...”

GPT Image 1.5 - Hand-lettered illustration for a vintage-style travel poster advertising VISIT KYOTO in large decorative type at the top, rendered in a retro 1950s tourism poster style with a stylized illustration of Kinkaku-ji temple below surrounded by maple trees in autumn colors, at the bottom in a banner ribbon the text JAPAN'S ANCIENT CAPITAL in smaller refined uppercase, and below that JAPAN NATIONAL TOURISM BOARD in the smallest text, the word KYOTO featuring decorative elements integrated into the letterforms — the K incorporating a torii gate shape and the O containing a zen circle, limited color palette of vermillion, gold, deep green, and cream, slight paper texture overlay, the overall composition following classic WPA poster proportions
?

GPT Image 1.5

4.93

Nano Banana Pro - Hand-lettered illustration for a vintage-style travel poster advertising VISIT KYOTO in large decorative type at the top, rendered in a retro 1950s tourism poster style with a stylized illustration of Kinkaku-ji temple below surrounded by maple trees in autumn colors, at the bottom in a banner ribbon the text JAPAN'S ANCIENT CAPITAL in smaller refined uppercase, and below that JAPAN NATIONAL TOURISM BOARD in the smallest text, the word KYOTO featuring decorative elements integrated into the letterforms — the K incorporating a torii gate shape and the O containing a zen circle, limited color palette of vermillion, gold, deep green, and cream, slight paper texture overlay, the overall composition following classic WPA poster proportions
?

Nano Banana Pro

3.93

GPT nailed the decorative typography — correctly integrating the torii gate into the K letterform. NBP produced an equally beautiful poster but misplaced the decorative element, making the title hard to read.

Architectural visualization

NBP wins 6 of 10 architecture prompts, GPT wins 3, 1 tie

prompt-0158

“Architectural visualization 3D render using a vertical cutaway section view of a five-story modern apartment building, slicing through the center to...”

GPT Image 1.5 - Architectural visualization 3D render using a vertical cutaway section view of a five-story modern apartment building, slicing through the center to reveal all floors simultaneously like a dollhouse, each apartment showing a different resident's lifestyle — ground floor: a young couple's minimalist studio with open kitchen, second floor: a family apartment with children's toys scattered and a baby crib in the bedroom, third floor: an elderly person's traditional-decorated flat with heavy curtains and bookshelves, fourth floor: a work-from-home professional's loft with multiple monitors and a standing desk, penthouse: a luxury unit with double-height ceilings and a rooftop terrace, consistent structural elements running through all floors — load-bearing walls aligning vertically, plumbing stacks in the same position, stairwell on the right side, each floor at correct ceiling height with visible floor slabs, rendered in V-Ray with section line highlighted in red
?

GPT Image 1.5

3.51

Nano Banana Pro - Architectural visualization 3D render using a vertical cutaway section view of a five-story modern apartment building, slicing through the center to reveal all floors simultaneously like a dollhouse, each apartment showing a different resident's lifestyle — ground floor: a young couple's minimalist studio with open kitchen, second floor: a family apartment with children's toys scattered and a baby crib in the bedroom, third floor: an elderly person's traditional-decorated flat with heavy curtains and bookshelves, fourth floor: a work-from-home professional's loft with multiple monitors and a standing desk, penthouse: a luxury unit with double-height ceilings and a rooftop terrace, consistent structural elements running through all floors — load-bearing walls aligning vertically, plumbing stacks in the same position, stairwell on the right side, each floor at correct ceiling height with visible floor slabs, rendered in V-Ray with section line highlighted in red
?

Nano Banana Pro

5.00

This prompt specifies different residents on each floor. NBP placed every lifestyle detail on the correct floor. GPT swapped the floor contents and missed the double-height penthouse ceilings — a 1.49-point gap, the largest in our benchmark.

Character design & concept art

GPT wins 11 of 15 character/concept art prompts, NBP wins 4

prompt-0119

“Concept art turnaround sheet of a post-apocalyptic wanderer showing front, side, and three-quarter views, consistent proportions across all views with...”

GPT Image 1.5 - Concept art turnaround sheet of a post-apocalyptic wanderer showing front, side, and three-quarter views, consistent proportions across all views with matching height and build, weathered face with asymmetric scarring on the right cheek, prosthetic left leg visible below the knee with mechanical joint detail, layered clothing showing correct overlap and material weight, hands wrapped in dirty bandages with fingertips exposed
?

GPT Image 1.5

4.43

Nano Banana Pro - Concept art turnaround sheet of a post-apocalyptic wanderer showing front, side, and three-quarter views, consistent proportions across all views with matching height and build, weathered face with asymmetric scarring on the right cheek, prosthetic left leg visible below the knee with mechanical joint detail, layered clothing showing correct overlap and material weight, hands wrapped in dirty bandages with fingertips exposed
?

Nano Banana Pro

3.37

Turnaround sheets require consistency across views — the same details on the same side in every pose. NBP rendered each view beautifully in isolation, but the prosthetic leg switched sides between views and the scar appeared on the wrong cheek. GPT kept details consistent.

Product photography

GPT wins 5 of 10 product prompts, NBP wins 4, 1 tie — but on detailed luxury objects, NBP has a clear edge

prompt-0121

“Commercial product photograph of a luxury Swiss automatic watch on a polished obsidian surface, the dial showing correct hour marker placement at all...”

GPT Image 1.5 - Commercial product photograph of a luxury Swiss automatic watch on a polished obsidian surface, the dial showing correct hour marker placement at all twelve positions with matching lume pip sizes, three sub-dials for chronograph functions with properly scaled subsidiary hands, date window at three o'clock magnified by cyclops lens showing the number 15 in correct font, crown and two pushers on the right side with knurled grip texture at accurate scale, exhibition caseback revealing the decorated movement with Geneva stripes on the rotor and blued steel screws in the bridge plates, bracelet links showing progressive size reduction from the case to the clasp, shot with focus stacking on a Fujifilm GFX 100S with 120mm GF Macro at f/5.6, Broncolor Siros strobe with strip softbox creating a clean specular highlight following the case contour
?

GPT Image 1.5

3.55

Nano Banana Pro - Commercial product photograph of a luxury Swiss automatic watch on a polished obsidian surface, the dial showing correct hour marker placement at all twelve positions with matching lume pip sizes, three sub-dials for chronograph functions with properly scaled subsidiary hands, date window at three o'clock magnified by cyclops lens showing the number 15 in correct font, crown and two pushers on the right side with knurled grip texture at accurate scale, exhibition caseback revealing the decorated movement with Geneva stripes on the rotor and blued steel screws in the bridge plates, bracelet links showing progressive size reduction from the case to the clasp, shot with focus stacking on a Fujifilm GFX 100S with 120mm GF Macro at f/5.6, Broncolor Siros strobe with strip softbox creating a clean specular highlight following the case contour
?

Nano Banana Pro

4.30

Both models produced stunning commercial-grade photos, but the details diverged. GPT rendered impossible geometry (crown visible in the caseback view) while NBP maintained more plausible object structure. Neither perfectly rendered the intricate watch movement — a frontier challenge for all AI image models.

Food & hospitality

NBP wins 3 of 5 food prompts, GPT wins 2 — but for complex scenes with human interaction, GPT has the advantage

prompt-0133

“Busy Saturday morning brunch restaurant scene, a waiter carrying a tray of three plated dishes navigating between occupied tables, the tray balanced...”

GPT Image 1.5 - Busy Saturday morning brunch restaurant scene, a waiter carrying a tray of three plated dishes navigating between occupied tables, the tray balanced on one hand at shoulder height showing correct wrist angle and spread fingers beneath, each plate containing a different recognizable breakfast — eggs benedict, a stack of pancakes, and avocado toast — tables in background showing consistent place settings with silverware on correct sides
?

GPT Image 1.5

4.80

Nano Banana Pro - Busy Saturday morning brunch restaurant scene, a waiter carrying a tray of three plated dishes navigating between occupied tables, the tray balanced on one hand at shoulder height showing correct wrist angle and spread fingers beneath, each plate containing a different recognizable breakfast — eggs benedict, a stack of pancakes, and avocado toast — tables in background showing consistent place settings with silverware on correct sides
?

Nano Banana Pro

4.28

The food looks great in both images. The difference is the waiter — GPT rendered anatomically correct hand positioning for one-handed tray carrying, while NBP produced rubbery wrists and malformed fingers. When a scene combines food with human interaction, anatomy accuracy becomes the deciding factor.

Fashion & editorial

NBP wins 2 of 5 fashion prompts, GPT wins 1, 2 ties — NBP averages 4.70 vs GPT's 4.48

prompt-0109

“High fashion editorial photograph of a model emerging from a swimming pool at twilight, water cascading off a metallic gold lame gown that clings to...”

GPT Image 1.5 - High fashion editorial photograph of a model emerging from a swimming pool at twilight, water cascading off a metallic gold lame gown that clings to the body when wet revealing fabric weight and drape behavior different from dry fabric, hair slicked back with water droplets catching the fading daylight as crystalline pinpoints, the pool water surface disturbed in concentric ripples radiating outward from the model's movement, wet footprints on the travertine pool deck showing the path of approach, underwater pool lights creating a turquoise glow that illuminates the model from below, shot on Nikon Z9 with 70-200mm f/2.8 at 135mm, two Profoto B10 Plus heads with colored gels — amber camera left and cyan camera right — creating a complementary split lighting scheme, art directed in the style of Tim Walker meets Helmut Newton
?

GPT Image 1.5

3.56

Nano Banana Pro - High fashion editorial photograph of a model emerging from a swimming pool at twilight, water cascading off a metallic gold lame gown that clings to the body when wet revealing fabric weight and drape behavior different from dry fabric, hair slicked back with water droplets catching the fading daylight as crystalline pinpoints, the pool water surface disturbed in concentric ripples radiating outward from the model's movement, wet footprints on the travertine pool deck showing the path of approach, underwater pool lights creating a turquoise glow that illuminates the model from below, shot on Nikon Z9 with 70-200mm f/2.8 at 135mm, two Profoto B10 Plus heads with colored gels — amber camera left and cyan camera right — creating a complementary split lighting scheme, art directed in the style of Tim Walker meets Helmut Newton
?

Nano Banana Pro

4.16

Both models struggled with the wet footprints — a challenging physics detail. GPT's footprints point the wrong direction (physics scored 2/5), while NBP's are too dark but directionally correct. NBP also left studio lights visible in the background, but the overall image held together better.

Prompt-Level Results

Across 193 shared prompts, GPT Image 1.5 wins 73 while Nano Banana Pro wins 68 — with 52 ties. Neither model dominates; the winner depends on the specific prompt.

73

GPT wins

52

Ties

68

NBP wins

A “win” is defined as a score difference greater than 0.01 on a given prompt.

GPT's Content Policy Restrictions

GPT Image 1.5 refused to generate 7 of our 200 benchmark prompts due to OpenAI's content safety policies. Nano Banana Pro completed all 200. The rejected prompts fell into two categories:

Human figures in dynamic poses (4 prompts)

  • Two armored knights in combat with anatomical detail
  • Street dancer in a breakdance windmill with muscle detail
  • Ballet performer mid-grand-jeté in abandoned subway
  • Cybernetic martial artist character sheet with biomechanical detail

Anime-style illustrations (3 prompts)

  • Anime sunset scene with cherry blossoms (Makoto Shinkai style)
  • Magical girl character in transformation pose
  • Fantasy floating shrine above bioluminescent ocean

This matters if your workflow involves detailed human anatomy, action poses, or anime-style content. NBP handled all of these without issue. The overall scores above are computed only on the 193 prompts both models completed, so GPT's score is not penalized for these refusals — but the restricted prompt coverage is a real limitation.

Strengths and Limitations

GPT Image 1.5

Strengths

  • +Leads overall (4.64) — wins more individual prompts (73 vs 68)
  • +Stronger on marketing/branding, concept art, character design (wins 11 of 15)
  • +Better anatomy and multi-view consistency for character turnaround sheets
  • +Handles complex multi-element scenes (brunch restaurant, battle scenes)
  • +Slightly cheaper ($0.133 vs $0.138)

Limitations

  • −Refused 7 of 200 prompts due to content policy (anime, combat, dance poses)
  • −Weaker on architectural visualization (wins only 3 of 10)
  • −Can produce impossible geometry on complex objects (e.g. watch caseback views)

Nano Banana Pro

Strengths

  • +Dominates architectural visualization (wins 6 of 10) and fashion (avg 4.70 vs 4.48)
  • +Completed all 200 benchmark prompts — no content restrictions
  • +Stronger material rendering (metal, glass, fabric, food textures)
  • +Better at following detailed structural specifications in prompts

Limitations

  • −Slightly lower overall score (4.62 vs 4.64)
  • −Weaker on multi-view consistency — details can shift between views
  • −Most expensive model in our benchmark ($0.138)

The Verdict

Choose GPT Image 1.5 if...

You work with marketing materials, character design, concept art, or complex multi-element scenes. GPT handles text rendering, multi-view consistency, and human anatomy better.

Choose Nano Banana Pro if...

You work with architectural visualization, fashion editorial, or prompts requiring detailed structural specifications. NBP renders materials, interiors, and spatial layouts more faithfully.

Either way...

Both models score above 4.6 and produce excellent results on most prompts. The 0.023 overall gap is small — but on specific use cases the difference can exceed 1.0 points. Use VibeDex to check which model is best for your specific prompt.

Not Sure Which Model Fits Your Workflow?

GPT and NBP trade wins depending on the prompt. Describe your use case and we'll tell you which model scores highest for your specific needs.

Try the recommendation engine

Related Benchmarks

Both models also rank in the top 5 for text rendering — see our text rendering benchmark for scores across all 18 models.

Looking for a cheaper alternative? The Flux family comparison covers models from $0.001 to $0.070 with strong results.

Methodology: Rankings and scores in this article are based on VibeDex's benchmark of 20 AI image generation models evaluated across 200+ prompts. Every image is scored by AI-powered visual judges across four quality dimensions: Visual Fidelity, Physics & Logic, Subject Integrity, and Instruction Adherence. Scores are weighted by prompt intent. See our full methodology

Models not included in our benchmark (such as Midjourney, Stable Diffusion XL/3, Adobe Firefly, and DALL-E 3) are not represented in these rankings.

FAQ

Is GPT Image 1.5 better than Nano Banana Pro?

It depends on your use case. GPT Image 1.5 leads slightly overall (4.64 vs 4.62) and wins more individual prompts (73 vs 68). But Nano Banana Pro wins 3 of 4 quality dimensions — visual fidelity (4.99 vs 4.90), physics (4.66 vs 4.34), and subject integrity (4.51 vs 4.44). Instruction adherence is tied (4.63). NBP excels on raw image quality and material rendering; GPT wins on specific use cases like character design and multi-view consistency. Note that GPT was unable to generate 7 of our 200 benchmark prompts due to content policy restrictions.

Which is cheaper, GPT Image 1.5 or Nano Banana Pro?

GPT Image 1.5 is slightly cheaper at $0.133/image vs $0.138/image for Nano Banana Pro. The difference is negligible — about $0.50 per 100 images.

How many prompts were tested in this comparison?

We compared both models across 193 shared prompts covering photorealism, illustration, typography, product shots, concept art, and edge cases. Nano Banana Pro completed all 200 benchmark prompts, but GPT Image 1.5 refused 7 due to content policy restrictions. Scores are compared only on the 193 prompts both models completed.

What prompts did GPT Image 1.5 refuse to generate?

GPT refused 7 prompts: 4 involving detailed human figures in dynamic poses (combat, breakdancing, ballet, martial arts with anatomical detail) and 3 anime-style illustrations. These were blocked by OpenAI's content safety policies. Nano Banana Pro generated all 7 without issue.

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