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How to Prompt GPT Image 2.5 Like a Pro: The Complete 2026 Guide

Learn how to write better GPT Image 2.5 prompts with reusable formulas, practical examples, reference-image workflows, precise editing tips

CometAPI
AnnaAI model and API research team
Updated Sep 21, 2026 14 min read
How to Prompt GPT Image 2.5 Like a Pro: The Complete 2026 Guide
Use this pattern

Make the first API call.

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_COMETAPI_KEY",
    base_url="https://api.cometapi.com/v1",
)

response = client.chat.completions.create(
    model="gpt-5-mini",
    messages=[{"role": "user", "content": "Build this workflow."}],
)

print(response.choices[0].message.content)

TL;DR GPT Image 2.5 changes image prompting in one important way: a good prompt no longer describes only what you want to create. For editing and reference-based generation, it should also define what must not change.

That matters because GPT Image 2.5 is designed for more precise editing and stronger reference preservation. OpenAI says the model is better at changing only the requested element while keeping the subject, composition, and surrounding details intact.

Good GPT Image 2.5 Prompt = Deliverable + Subject + Scene + Composition + Visual Direction + Exact Text + Constraints + Output

Good Editing Prompt = Change Target + Preserve List + Integration Rules + Exclusions + Output

The second formula is especially important. Instead of saying โ€œChange the background to a beach,โ€ write: โ€œReplace only the background with a quiet Mediterranean beach at sunset. Keep the person, face, pose, clothing, camera position, framing, lighting direction, and foreground unchanged.โ€

Key Takeaways

  • GPT Image 2.5 improves fidelity, multi-turn consistency, text rendering, and speed; Flare is the recommended starting point for most users.
  • Core generation formula: Deliverable + Subject + Composition + Style + Exact Text (in quotes) + Constraints/Exclusions.
  • For edits the golden rule is โ€œChange only X. Preserve [full list of identity, pose, lighting, geometry, text, style].โ€
  • Multiple reference images succeed when each is given an explicit job (subject, clothing, background, palette, etc.).
  • Transparent backgrounds, exact typography, and sequential editing are markedly stronger when prompted correctly and parameters are set properly.
  • Flare prioritizes speed and volume; Sunburst prioritizes edit precision and final-asset fidelity. Both share the same token rates.
  • CometAPI offers unified, cost-effective access to gpt-image-2.5-flare and gpt-image-2.5-sunburst via familiar OpenAI-compatible routes.

What Is GPT Image 2.5

OpenAI released ChatGPT Images 2.5 on September 8, 2026. The update focuses on sharper detail, more natural lighting and texture, reference-image fidelity, precise edits, and stronger consistency across multiple editing turns. OpenAI also reports up to 50% lower image-generation latency compared with Images 2.0.

For developers, the family is split into two API models:

  • GPT-Image-2.5 Flare โ€” optimized for fast, high-quality everyday generation and high-volume workflows.
  • GPT-Image-2.5 Sunburst โ€” optimized for demanding generation and editing workflows where precision matters more than latency.

Developers can also use the GPT Image 2.5 API in CometAPI, including the gpt-image-2.5-flare and gpt-image-2.5-sunburst model identifiers.

Benchmark and capabilities

Arena text-to-image benchmarkGPT Image 2.5 SunburstGPT Image 2.5 FlareGPT Image 2
Text-to-image score1421 ยฑ 131399 ยฑ 131381 ยฑ 4
Text-to-image rank#1#2#3
Single-image-edit score1520 ยฑ 91491 ยฑ 91461 ยฑ 3
Single-image-edit rank#1#2#3

Independent tests and early Arena rankings placed both models at the top of text-to-image and image-editing leaderboards shortly after launch, with clear gains in composition, detail, style fidelity, subject preservation, and speed (Flare often finishing in ~20โ€“40 seconds vs. significantly longer prior generations in some benchmarks).

Key capabilities include text + image inputs, image outputs up to roughly 4K (with constraints: edges multiples of 16, max ~3840 px per side, aspect ratio โ‰ค 3:1), transparent backgrounds (PNG/WebP), quality tiers (low โ†’ max), progressive previews, inpainting/area-specific editing, and strong support for multi-reference and sequential editing. OpenAI reports more than 3 billion images created weekly across ChatGPT Images and the GPT-Image API family.

General Formula for Generating and Editing GPT Image 2.5

The Most Important Rule: Change vs Preserve

This distinction is the single highest-leverage habit for GPT Image 2.5.

Generation (new image from text or references)
Describe everything you want to appear. Be concrete about the subject, framing, lighting, materials, colors, and what must not appear.

Editing (image-to-image or multi-turn refinement)

  1. Name exactly one change.
  2. Explicitly list everything that must remain unchanged (identity, pose, camera angle, framing, lighting direction, shadows, background elements, existing text, colors, geometry, overall style).
  3. Describe how the new element should integrate with the existing light, perspective, texture, and contact shadows.
  4. Add clear exclusions (no extra text, no logos, no watermarks, no heavy retouching).

Vague multi-change prompts or missing preserve lists cause cumulative drift. Restate the preserve list on every turn. When a region must stay pixel-identical, composite the approved local edit back into the original master rather than trusting the model alone.

Minimal generation skeleton

[Deliverable / intended use] + Subject + Composition + Style / lighting / materials + Exact text in quotation marks + Constraints and exclusions

Minimal edit skeleton

Change only [specific element] to [new description]. Preserve [identity, pose, framing, lighting, shadows, background, text, colors, style]. Match the new element to existing light and geometry. Do not add [unwanted elements].

How GPT Image 2.5 Prompting Works

OpenAIโ€™s official prompting guidance is straightforward: start with the image you need, then describe the subject, composition, style, and constraints. For edits, clearly separate the requested change from the details that must stay the same. Refine one thing at a time and inspect every result.Structure prompts as Subject โ†’ Composition โ†’ Style โ†’ Text (quoted) โ†’ Constraints. Assign clear roles to every reference image, iterate one change at a time, and set size/quality/background as API parameters rather than prompt text.

Subject

Name the primary person, object, or scene with visible, testable details: appearance, clothing, pose, action, relative scale, and interaction with objects.
Example: โ€œA young archivist with a short auburn bob, round black glasses, and a navy work coat holding a sealed paper envelope with a red wax moon emblem.โ€

Composition

Specify framing, camera height and angle, subject placement (centered, left third, etc.), negative space, depth of field, and what must be visible (full body with feet, medium close-up, etc.).
Example: โ€œFull body, feet visible, low eye-level camera. Character on the left third; endless archive shelves recede behind her. Clean dark space at upper right for later title placement.โ€

Style

Describe the visual medium, lighting (source + direction), materials, color palette, texture, and realism level. Prefer concrete visual language over pure mood adjectives. Explicitly request โ€œphotorealistic,โ€ โ€œreal photograph,โ€ film grain, or a named artistic style when required.
Example: โ€œDetailed hand-painted anime background, restrained cel shading, natural proportions. One warm desk lamp against cool blue moonlight from high windows.โ€

Text

Place every required string inside quotation marks. Specify location, hierarchy, approximate typography, and how many times the text should appear. Spell unusual or brand names letter-by-letter when critical. Always request โ€œno other text.โ€
Example: the headline "Open Late" in bold condensed type across the top, and "Thursday to Sunday" in smaller type at the bottom. No other text.

Constraints / Exclusions

List what must not appear and what must remain unchanged. High-value exclusions include no extra text, no logos, no watermarks, no heavy retouching, and no unwanted objects.

For longer or more complex requests, use labeled sections (SCENE / SUBJECT / STYLE / TEXT / CONSTRAINTS). This improves readability and makes later edits easier to maintain.

Critical technical note: Set model, quality, size (or aspect), and background (auto / opaque / transparent) as API parameters. Do not rely on the prompt text to enforce resolution or transparency.

How Do You Use Multiple Reference Images With GPT Image 2.5?

GPT Image 2.5 accepts multiple image inputs. Results improve dramatically when every reference is given an explicit role.

Recommended pattern:

  1. Number or clearly name each reference image.
  2. State its precise job: primary subject identity, clothing/style reference, background/setting, color palette only, lighting reference, etc.
  3. Describe how the elements should combine and which parts move where.
  4. Restate preservation constraints for the primary subject and any protected details.

Example: โ€œUse image 1 as the product (matte black water bottle with exact label text). Use image 2 only for the pale concrete ledge and natural outdoor lighting direction. Place the bottle from image 1 on the ledge from image 2, matching the existing soft shadows and light angle. Preserve the bottleโ€™s exact shape, label text, colors, and reflections. Do not change the concrete texture or add any extra objects.โ€

Clear role assignment prevents unwanted hybridization of subjects or styles.

Advanced Prompting Techniques

Exact Text & Typography Tutorial

  • Always enclose required strings in quotation marks.
  • Specify position, hierarchy, approximate weight and style, and the number of times the text should appear.
  • Request โ€œno other text,โ€ โ€œno logos,โ€ and โ€œno watermarks.โ€
  • For dense layouts or multiple fonts, test medium or high quality and visually verify spelling and legibility in the output.
  • Critical brand names can be spelled letter-by-letter for extra reliability.

Transparent Backgrounds

Set background="transparent" in the API call (or the equivalent UI control) and request PNG or WebP output. Explicitly ask for clean edges and nothing behind the subject. Inspect the alpha channel carefully around hair, glass, fine details, and contact areas. Add exclusions such as โ€œno background elements, no drop shadows unless requested.โ€ Transparent generation is significantly more reliable in 2.5 when the parameter and prompt constraints are both correct.

Multi-turn Editing Workflow

  1. Start from a strong base generation or approved reference.
  2. Feed the previous output back as the new input image.
  3. Request exactly one change.
  4. Restate the complete preserve list on every turn.
  5. Inspect the result before continuing.
  6. For regions that must remain pixel-perfect, composite the approved local edit into the original master image.

This disciplined loop takes full advantage of GPT Image 2.5โ€™s improved multi-turn consistency while minimizing cumulative drift.

Flare vs. Sunburst: Which Model Fits Which Prompt?

CriterionGPT-Image-2.5 FlareGPT-Image-2.5 Sunburst
Primary strengthSpeed + high everyday qualityEdit precision & final-asset fidelity
LatencyUp to ~50% lower than GPT Image 2Longer generation times
Best use casesSocial content, prototyping, high-volume, rapid iterationProduction campaign creative, polished product shots, complex multi-turn edits
Quality vs GPT Image 2HigherHighest control / tightest preservation
Recommended starting pointMost workflowsWhen quality or edit precision is the bottleneck
Token pricingSame rates for bothSame rates for both
Transparent backgrounds & quality tiersFully supported (low โ†’ max)Fully supported

Practical decision rule: Explore ideas, generate variations, and iterate quickly on Flare. When you need the final polished version or when a complex edit sequence begins to drift, re-run the identical prompt + references + settings on Sunburst and compare. Many production teams keep both models available and route traffic accordingly.

Prompt Templates (Ready to Adapt)

1. Clean Product Hero

Purpose: Ecommerce or landing-page hero, square or 4:5.
Subject: [exact product description including materials and any label text in quotes].
Composition: Centered or slight three-quarter view, soft contact shadow, generous negative space at top for headline.
Style: Clean studio lighting from the left, photorealistic, high texture detail.
Constraints: No extra text, no logos, no people reflections, seamless background.

2. Exact-Text Poster / Ad

A vertical poster. Headline โ€œYOUR EXACT HEADLINEโ€ in bold condensed sans-serif across the upper third. Subhead โ€œSecondary line hereโ€ in smaller weight directly below. [Full scene and subject description]. [Style]. No other text or logos.

3. Precise Single-Element Edit

Change only the [specific element] to [new description]. Preserve the subjectโ€™s exact face/identity, pose, clothing details, camera angle, lighting direction, shadows, background, and all existing text. Match the new elementโ€™s lighting, perspective, and contact shadows to the original scene. Do not add any new objects, text, or watermarks.

4. Multi-Reference Character Consistency

Use image 1 for the characterโ€™s face, body proportions, and identity. Use image 2 only for the outfit and fabric texture. Place the character from image 1 wearing the outfit from image 2 inside [scene description]. Match the lighting direction of image 1. Preserve identity and pose exactly. No extra accessories or text.

5. Transparent Cutout / Asset

[Detailed subject description] isolated on a pure transparent background. Clean edges, no drop shadow, no background elements, no floor contact shadow unless explicitly requested. Photorealistic. Output ready for compositing.

Replace the bracketed sections with your specifics and always restate constraints on subsequent editing turns.

Why Prompts Fail

Common failure patterns and how to fix them:

  • Relying on vague mood words (โ€œcozy,โ€ โ€œepic,โ€ โ€œpremiumโ€) without attached visual detail โ†’ add concrete scale, light direction, materials, and color.
  • Packing multiple changes into one prompt โ†’ limit to one change per turn.
  • Omitting or shortening the preserve list on later edits โ†’ details drift; restate the full list every time.
  • Exact text not placed in quotation marks or without location/typography guidance โ†’ wrong words or extra text appear.
  • Reference images uploaded without assigned roles โ†’ the model blends them unpredictably.
  • Expecting a higher quality tier to rescue a weak description โ†’ the prompt carries the result; quality mainly affects refinement, cost, and latency.
  • Using special syntax, weights, or โ€œmasterpiece 8K ultra detailedโ€ keyword stacking โ†’ clear, ordered sentences consistently outperform keyword stuffing.
  • Forgetting integration instructions on edits โ†’ new elements look composited rather than natural.

Higher quality settings (xhigh or max) help with dense text, fine detail, or complex layouts, but they cannot compensate for an underspecified prompt.

PT Image 2.5 Prompting Mistakes Should You Avoid?

MistakeWeak approachBetter approach
No deliverableโ€œMake something cinematicโ€โ€œCreate a 4:5 paid-social product photographโ€
Vague editโ€œImprove the backgroundโ€โ€œReplace only the background withโ€ฆโ€
No preservation rulesโ€œChange the shirtโ€Lock face, pose, camera, and background
Unassigned referencesโ€œUse these imagesโ€Give each reference one role
Too many changesFive major edits in one requestOne controlled change per pass
Assuming prompt = complianceTrust the generationPerform visual QA

Accessing GPT Image 2.5 Through CometAPI

CometAPI provides OpenAI-compatible access to both gpt-image-2.5-flare and gpt-image-2.5-sunburst under a single API key and the familiar /v1/images/generations and edits endpoints. Benefits include centralized authentication and billing, competitive token rates, easy switching between Flare and Sunburst, usage visibility, and the ability to combine image generation with the broader catalog of 500+ models without managing multiple vendor accounts.

A typical migration requires only changing the base URL to https://api.cometapi.com/v1, supplying your CometAPI key, and selecting the desired model ID. This setup is especially valuable for production pipelines that need to A/B the two variants, control costs, or route different quality tiers efficiently.

For the latest parameter lists, pricing, and code examples, consult CometAPIโ€™s image generation documentation alongside OpenAIโ€™s official image prompting guide.

Conclusion

GPT Image 2.5 rewards clarity, structure, and discipline. Define the deliverable, describe the visible subject and composition with concrete detail, name the style through lighting/materials/color, put exact text in quotes, and (for every edit) ruthlessly separate the single change from the full preserve list. Give every reference image a clear job, iterate one decision at a time, and let API parameters handle size, quality, and transparency. Start exploration and high-volume work on Flare; move to Sunburst when final precision or complex edit sequences demand it.

Master the Change-vs-Preserve rule and the Subjectโ€“Compositionโ€“Styleโ€“Textโ€“Constraints structure, and GPT Image 2.5 becomes a reliable production tool rather than a source of endless regeneration. Pair it with a unified gateway such as CometAPI and you gain both creative power and operational simplicity.

FAQs

Should GPT Image 2.5 prompts be long?

Not necessarily. A long prompt full of vague adjectives can be weaker than a short prompt with precise composition and preservation instructions. Include detail where failure would matter.

How do I stop GPT Image 2.5 from changing the whole image?

Use a narrow instruction such as โ€œChange only the jacket,โ€ then explicitly list what must remain unchanged: identity, pose, framing, camera position, lighting, background, text, and other approved elements.

How do I preserve a personโ€™s face?

Use a clear reference photo, assign it as the authoritative identity reference, and state which characteristics must remain stable. Do not rely entirely on โ€œsame person.โ€

How do I make GPT Image 2.5 generate exact text?

Provide the final copy verbatim, state where it should appear, specify its hierarchy, and instruct the model not to add other words. Always verify the final text visually.

Can GPT Image 2.5 create transparent PNG images?

Yes. Set the background to transparent and use PNG or WebP output.

Can GPT Image 2.5 generate 4K images?

Yes. The documented maximum includes 3840 ร— 2160 landscape and 2160 ร— 3840 portrait output. Resolutions above 2560 ร— 1440 are experimental, and custom dimensions must satisfy the APIโ€™s divisibility and aspect-ratio constraints.

Is GPT Image 2.5 better for editing than GPT Image 2?

OpenAI highlights improved precision editing, reference preservation, and multi-turn consistency. Arenaโ€™s early preference results also favored both 2.5 variants at the dated snapshot, but these preliminary rankings can change.

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Published on Sep 21, 2026
Last updated Sep 21, 2026
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Reviewed for clarity, source attribution and current API terminology.

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