Best AI Image Models for Realistic Portraits: A Same-Prompt Test
Thirty identical portrait prompts, completion data from five models, and the failure modes Reddit users notice in side-by-side tests.
This comparison uses 30 adult portrait, selfie, fashion, and lifestyle prompts run through Nano Banana 2, Seedream 4.5, GPT Image 2 Medium, Grok, and Seedream V5. Completion rate is measured directly. Visual preference is kept separate because a model can accept every prompt and still produce the weaker portrait.
What each result means
| Model | Completed | Use it when | Watch for |
|---|---|---|---|
| Seedream 4.5 | 30/30 | You need a varied queue to finish reliably and preserve references | A complete result still needs a quality and identity review |
| Seedream V5 | 29/30 | You want a close reliability challenger with a different visual treatment | Newer styling is not automatically better for an existing character |
| Nano Banana 2 | 27/30 | Natural phone-photo portraits, reference consistency, and conversational edits matter | Complex scenes can still miss identity or background logic |
| Grok | 22/30 | You want another creative interpretation for fashion and outdoor scenes | Acceptance was less predictable in bedroom and suggestive prompts |
| GPT Image 2 Medium | 11/30 | The specific prompt fits its rules and its polished interpretation suits the brief | It was the strictest model in this adult-oriented set |
Reddit side-by-sides expose different failures
A 59-vote r/Bard same-prompt test asked three Nano Banana generations to show a painter creating a mural of herself. Nano Banana 2 came closest to keeping the painter and mural face consistent, but the author still called it an incremental improvement rather than perfect one-to-one likeness.
A 50-vote GPT Image 2 versus Nano Banana 2 comparison favored Nano Banana 2 for casual phone-photo skin and lighting, while replies pointed out that believable anatomy and object interaction can reverse the winner. A 129-vote r/Bard comparison split again: some readers preferred GPT's color and lighting, others preferred Nano Banana's background detail, and several said the copied prompt favored one model's default style.
Inspect these four things at full size
| Check | Failure that thumbnails hide |
|---|---|
| Identity | Eye spacing, jaw, hairline, and age shift between scenes |
| Skin and light | Waxy texture, contradictory catchlights, or beauty-ad smoothing in a supposedly candid shot |
| Physical logic | Hands that do not hold objects, impossible reflections, floating jewelry, or background furniture that merges |
| Production cost | Blocked attempts, rerolls, face repair, inpainting, and manual retouching before one image is usable |
Which model should you start with?
- Start with Nano Banana 2 for a natural-looking single portrait or conversational reference edit.
- Start with Seedream 4.5 for a mixed production queue where completion and reference preservation matter.
- Keep Seedream V5 beside 4.5 when a different contrast, color, or composition treatment may suit the scene.
- Treat Grok and GPT Image 2 as prompt-specific alternatives, not default winners from brand reputation.