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GPT Image 1.5 API Production Guide: Pricing, Latency Patterns, and Scaling Architecture

Jessie
Jessie
COO
December 18, 2025
8 min read
GPT Image 1.5 API Production Guide: Pricing, Latency Patterns, and Scaling Architecture
OpenAI introduced an improved ChatGPT Images experience and made the same model available via API as GPT Image 1.5 (gpt-image-1.5). The release highlights stronger instruction-following, more precise editing, improved dense text rendering, and image generation speeds up to 4× faster compared with prior iterations.
For B2B SaaS teams building creative tooling, ecommerce pipelines, or marketing automation, the key shift is not "prettier pictures"—it's more reliable edits that preserve important details (e.g., likeness, composition, branded elements) across iterations.
This guide focuses on production realities: pricing, latency patterns, safety rejections, and scalable system design, plus how a unified gateway approach (like EvoLink.ai) can reduce integration overhead across multiple image models.

Executive Summary: What GPT Image 1.5 Changes in Production

GPT Image 1.5 is positioned as OpenAI's most capable general-purpose text-to-image model at launch, with emphasis on:

  • Instruction following: more reliable changes "down to small details."
  • Editing & preservation: better at applying edits while keeping key elements consistent (including facial likeness and branded visuals across edits).
  • Text rendering: improved ability to render dense text within images.
  • Speed: generation speeds up to 4× faster (reported by OpenAI).
What it doesn't magically solve: latency variability under load, safety-filter rejections, and cost spikes when you scale high-quality or high-resolution generation. Those are architectural problems you must design for.

Competitive Landscape: GPT Image 1.5 vs Nano Banana Pro vs FLUX

Choosing an image model in 2025 is about workflow fit (editing fidelity, text rendering, control surface, integration constraints), not just "aesthetic preference".
CategoryGPT Image 1.5 (OpenAI)Nano Banana Pro (Google DeepMind)FLUX Family (Black Forest Labs)
PositioningGeneral-purpose image generation + strong editing & instruction adherenceBuilt on Gemini 3; focuses on "studio-quality precision/control" and clear textText-to-image + editing variants (e.g., Kontext / Fill); options for API usage and self-hosting
Text in imagesImproved dense text rendering"Generate clear text" for posters/diagramsVaries by model and workflow; strong editing-focused lineup
Editing & preservationEmphasis on precise edits preserving important details across editsEmphasis on precision/control for editsStrong editing catalog (Kontext / Fill etc.)
Takeaway: If your workload is brand-sensitive editing (logos, likeness, key visual continuity), GPT Image 1.5's official positioning is strong; if you need Google ecosystem controls and "studio-quality" knobs, Nano Banana Pro is a direct peer; if you prioritize configurable editing pipelines or self-hosting options, FLUX can be attractive depending on your infra constraints.

Production Performance: Latency Patterns and Reliability

In production, track Time-to-Result (TTR) as a distribution (p50/p95/p99), not a single "average".

Common latency drivers across image models:

  • Resolution & aspect ratio (larger outputs take longer)
  • Prompt complexity and iterative edits
  • Traffic spikes / queueing
  • Retry loops after safety rejections or transient failures
Design recommendation
  • Use timeouts + idempotency keys (or your own request IDs)
  • Add async job queues for long-running generations
  • Implement graceful fallbacks (lower quality, smaller size, or alternative model)
GPT Image 1.5 example 1
GPT Image 1.5 example 2
GPT Image 1.5 example 3

Safety Filters: Plan for Rejections as a First-Class Outcome

OpenAI's image APIs enforce safety policies; prompts or edits may be rejected. In production you should treat "rejected" as a normal outcome:

  • Show actionable UI feedback to users
  • Log rejection categories (when available)
  • Provide safe re-prompt suggestions
  • Avoid retry storms (rate-limit retries)

Pricing: Official GPT Image 1.5 Costs (Per Image + Tokens)

OpenAI publishes both:

  1. Per-image prices by quality and size
  2. Image token prices (for image inputs/outputs in token accounting)

Per-image prices (official)

Quality1024×10241024×15361536×1024
Low$0.009$0.013$0.013
Medium$0.034$0.05$0.05
High$0.133$0.2$0.2
OpenAI also states that GPT Image 1.5 image inputs and outputs are 20% cheaper than GPT Image 1.

Image token prices (official)

  • gpt-image-1.5: image tokens Input $8 / Output $32 per 1M tokens
  • gpt-image-1: image tokens Input $10 / Output $40 per 1M tokens
Why it matters: If your product does multi-step edits (upload → edit → re-edit), tokenized image I/O can materially affect unit economics. Your billing model should reflect that.

Developer Experience: What You Should Architect Around

Even when the model is strong, shipping a reliable product requires engineering for:

  1. Rate limits & backpressure (plan for 429s and queue requests)
  2. Schema drift across providers (different parameters, error codes, response formats)
  3. Observability (per-request cost, latency percentiles, failure reasons, fallback rates)

A unified gateway approach can reduce operational burden by:

  • Standardizing request/response formats across vendors
  • Adding routing rules (e.g., choose GPT Image 1.5 for text-heavy posters; choose another model for photoreal scenes when acceptable)
  • Implementing fallback strategies when a provider rejects or errors
  • Providing centralized usage analytics for cost and performance tracking

EvoLink provides a unified endpoint for GPT Image 1.5 that supports text-to-image, image-to-image, and image editing modes with asynchronous processing.

Endpoint: POST https://api.evolink.ai/v1/images/generations
Request parameters:
ParameterTypeRequiredDescription
modelstringYesUse gpt-image-1.5-lite
promptstringYesImage description, max 2000 tokens
sizeenumNo1:1, 3:4, 4:3, 1024x1024, 1024x1536, 1536x1024
qualityenumNolow, medium, high, auto (default)
image_urlsarrayNo1-16 reference images for editing, max 50MB each
nintegerNoNumber of images (currently supports 1)

Example: Text-to-Image

curl --request POST \
  --url https://api.evolink.ai/v1/images/generations \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "gpt-image-1.5-lite",
    "prompt": "A professional product photo of a sleek smartwatch on a marble surface, soft studio lighting, 4K quality",
    "size": "1024x1024",
    "quality": "high"
  }'

Example: Image Editing

curl --request POST \
  --url https://api.evolink.ai/v1/images/generations \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "gpt-image-1.5-lite",
    "prompt": "Change the background to a sunset beach scene, keep the product unchanged",
    "image_urls": ["https://your-cdn.example.com/product-photo.jpg"],
    "size": "1024x1024",
    "quality": "high"
  }'

Response format

The API returns an async task. Poll the task status using the returned ID:

{
  "created": 1757156493,
  "id": "task-unified-1757156493-imcg5zqt",
  "model": "gpt-image-1.5-lite",
  "status": "pending",
  "progress": 0,
  "task_info": {
    "can_cancel": true,
    "estimated_time": 100
  },
  "usage": {
    "credits_reserved": 2.5
  }
}
Note: Generated images expire after 24 hours. Download and store them promptly.
GPT Image 1.5 generation example 1
GPT Image 1.5 generation example 2

Conclusion

GPT Image 1.5 (gpt-image-1.5) is a major 2025 step for production image workflows, with OpenAI explicitly emphasizing better instruction following, more precise edits that preserve important details, improved text rendering, and up to 4× faster generation.

To ship reliably at scale, treat images as an infra problem: measure latency distributions, budget with official per-image pricing, handle safety rejections gracefully, and design routing/fallback patterns that protect user experience and unit economics.

If you're building multi-model image features, a unified API layer can simplify integration and accelerate iteration—without locking you into a single vendor.

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