GPT-5.4 vs GPT-5.5 Instant
GPT-5.4 (2026) and GPT-5.5 Instant (2026) are frontier reasoning models from OpenAI. GPT-5.4 ships a 1.05m-token context window, while GPT-5.5 Instant ships a 400k-token context window. On MMMU Pro, GPT-5.4 leads by 5.2 pts. On pricing, GPT-5.4 ranges from $2.50 to $5/1M input tokens by tier; GPT-5.5 Instant costs $5/1M input tokens. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
GPT-5.5 Instant is safer overall; choose GPT-5.4 when coding workflow support matters.
Decision scorecard
Local evidence first| Signal | GPT-5.4 | GPT-5.5 Instant |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | multimodal apps and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 1.05m | 400k |
| Cheapest output | $15/1M tokens | $30/1M tokens |
| Provider routes | 4 tracked | 1 tracked |
| Shared benchmarks | MMMU Pro leader | 1 shared |
Decision tradeoffs
- GPT-5.4 holds a shared-benchmark lead on MMMU Pro, ahead by 5.2 points.
- GPT-5.4 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GPT-5.4 has the lower cheapest tracked output price at $15/1M tokens.
- GPT-5.4 has broader tracked provider coverage for fallback and procurement flexibility.
- GPT-5.4 uniquely exposes Reasoning in local model data.
- Local decision data tags GPT-5.5 Instant for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
GPT-5.4
$5,750
Cheapest tracked route/tier: OpenAI API
GPT-5.5 Instant
$11,500
Cheapest tracked route/tier: OpenAI API
Estimated monthly gap: $5,750. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenAI API; start route-level A/B tests there.
- GPT-5.5 Instant is $15/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Reasoning before moving production traffic.
- Provider overlap exists on OpenAI API; start route-level A/B tests there.
- GPT-5.4 is $15/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- GPT-5.4 adds Reasoning in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-03-05 | 2026-05-05 |
| Context window | 1.05m | 400k |
| Parameters | — | — |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Commercial use | Commercial use with conditions | Commercial use with conditions |
| Knowledge cutoff | 2025-08 | 2025-08 |
Pricing and availability
| Pricing attribute | GPT-5.4 | GPT-5.5 Instant |
|---|---|---|
| Input price |
| $5/1M tokens |
| Output price |
| $30/1M tokens |
| Providers |
Capabilities
| Capability | GPT-5.4 | GPT-5.5 Instant |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | No |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | GPT-5.4 | GPT-5.5 Instant |
|---|---|---|
| MMMU Pro | 81.2 | 76.0 |
Deep dive
On shared benchmark coverage, MMMU Pro has GPT-5.4 at 81.2 and GPT-5.5 Instant at 76, with GPT-5.4 ahead by 5.2 points. The largest visible gap is 5.2 points on MMMU Pro, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on reasoning mode: GPT-5.4. Both models share vision, multimodal input, function calling, and tool use, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, GPT-5.4 lists tiered pricing: 0-272,000t is $2.50/1M input and $15/1M output; 272,000t+ is $5/1M input and $22.50/1M output, while GPT-5.5 Instant lists $5/1M input and $30/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts GPT-5.4 lower by about $6.25 per million blended tokens. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 4 providers versus 1, so concentration risk also matters.
Choose GPT-5.4 when coding workflow support, larger context windows, and lower cheapest-tier input-token cost are central to the workload. Choose GPT-5.5 Instant when coding workflow support are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, GPT-5.4 or GPT-5.5 Instant?
GPT-5.4 supports 1.05m tokens, while GPT-5.5 Instant supports 400k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is cheaper, GPT-5.4 or GPT-5.5 Instant?
GPT-5.4 lists tiered pricing: 0-272,000t is $2.50/1M input and $15/1M output; 272,000t+ is $5/1M input and $22.50/1M output. GPT-5.5 Instant lists $5/1M input and $30/1M output tokens on the cheapest tracked provider. Compare the tier you will actually use; cheap async pricing can overstate savings for interactive workflows. Provider discounts or batch pricing can still change the final bill.
Is GPT-5.4 or GPT-5.5 Instant open source?
GPT-5.4 is listed under Proprietary. GPT-5.5 Instant is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, GPT-5.4 or GPT-5.5 Instant?
Both GPT-5.4 and GPT-5.5 Instant expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, GPT-5.4 or GPT-5.5 Instant?
Both GPT-5.4 and GPT-5.5 Instant expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Where can I run GPT-5.4 and GPT-5.5 Instant?
GPT-5.4 is available on OpenAI API, OpenRouter, Vercel AI Gateway, and AWS Bedrock. GPT-5.5 Instant is available on OpenAI API. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-06-15. Data sourced from public model cards and provider documentation.