API cost decision in 10 seconds

OpenAI GPT Latest vs GPT-5.1 Chat

Pick GPT-5.1 Chat for lower cost; pick OpenAI GPT Latest only if the larger context window matters more.

Pricing data updated: 2026-05-26T11:08:00Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick GPT-5.1 Chat for lower cost; pick OpenAI GPT Latest only if the larger context window matters more.

On the standard 1M input plus 500K output workload, GPT-5.1 Chat is estimated at $6.25 vs $20 for OpenAI GPT Latest, saving $13.75 (68.8% lower).

Cost-first pickGPT-5.1 Chat

Context-first pickOpenAI GPT Latest

Sample savings$13.7568.8%

10x traffic gap$137.5

OpenAI GPT Latest has more context, but GPT-5.1 Chat saves $13.75 on the standard workload. At 10x that traffic, the same price gap is about $137.5. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

GPT-5.1 Chat stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	OpenAI GPT Latest	GPT-5.1 Chat
Input-heavy / RAG	5M input + 500K output	GPT-5.1 Chat	$40	$11.25
Balanced workload	1M input + 1M output	GPT-5.1 Chat	$35	$11.25
Output-heavy chatbot	1M input + 5M output	GPT-5.1 Chat	$155	$51.25

Cheaper input GPT-5.1 Chat $5 vs $1.25 / 1M

GPT-5.1 Chat is $3.75 cheaper per 1M input tokens (75% lower; 4x difference).

Cheaper output GPT-5.1 Chat $30 vs $10 / 1M

GPT-5.1 Chat is $20 cheaper per 1M output tokens (66.7% lower; 3x difference).

Larger context OpenAI GPT Latest 1.05M vs 128K

OpenAI GPT Latest has 922K more context (8.2x larger).

Sample workload GPT-5.1 Chat $20 vs $6.25

GPT-5.1 Chat is $13.75 cheaper on the standard workload (68.8% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

OpenAI GPT Latest Calculating… Estimated API cost

GPT-5.1 Chat Calculating… Estimated API cost

Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

GPT-5.1 Chat has the lower input price; GPT-5.1 Chat has the lower output price; OpenAI GPT Latest offers the larger context window. For the 1M input plus 500K output sample, GPT-5.1 Chat is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $20 for OpenAI GPT Latest and $6.25 for GPT-5.1 Chat.

Best Fit

Choose OpenAI GPT Latest when you care most about larger context window.

Choose GPT-5.1 Chat when you care most about lower input-token price, and lower output-token price.

Decision Notes

On the standard 1M input plus 500K output workload, GPT-5.1 Chat is estimated at $6.25 vs $20 for OpenAI GPT Latest, saving $13.75 (68.8% lower).
GPT-5.1 Chat is $13.75 cheaper on the standard workload (68.8% lower).
GPT-5.1 Chat is $3.75 cheaper per 1M input tokens (75% lower; 4x difference).
GPT-5.1 Chat is $20 cheaper per 1M output tokens (66.7% lower; 3x difference).
OpenAI GPT Latest has 922K more context (8.2x larger).

Head-to-Head Specs

Feature	OpenAI GPT Latest (OpenAI)	GPT-5.1 Chat (OpenAI)
Input Price prompt tokens per 1M	$5	$1.25
Completion Price per 1M tokens	$30	$10
Sample Workload Cost 1M input + 500K output	$20	$6.25
Context Window	1.05M	128K
Release Date	2026-04-27	2025-11-13

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	GPT-5.1 Chat	On the standard 1M input plus 500K output workload, GPT-5.1 Chat is estimated at $6.25 vs $20 for OpenAI GPT Latest, saving $13.75 (68.8% lower).
High-volume input processing	GPT-5.1 Chat	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	GPT-5.1 Chat	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	OpenAI GPT Latest	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

gpt-oss-120b (free) can replace OpenAI GPT Latest when lower sample workload cost matters most: $0.
gpt-oss-20b (free) can replace OpenAI GPT Latest when lower sample workload cost matters most: $0.
gpt-oss-20b can replace OpenAI GPT Latest when lower sample workload cost matters most: $0.1.
gpt-oss-120b can replace OpenAI GPT Latest when lower sample workload cost matters most: $0.13.

Larger context near this budget

Llama 4 Scout offers 10M context with $0.23 sample workload cost.
Grok 4.20 Multi-Agent offers 2M context with $5 sample workload cost.
Grok 4.20 offers 2M context with $2.5 sample workload cost.

Popular competitors

No popular competitor is currently available.

Cheaper alternatives

Review low-cost models sorted by a standard 1M input plus 500K output workload.

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Larger context alternatives

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Provider catalogs

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OpenAI catalog

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OpenAI GPT Latest

This model always redirects to the latest model in the OpenAI GPT family.

GPT-5.1 Chat

GPT-5.1 Chat (AKA Instant is the fast, lightweight member of the 5.1 family, optimized for low-latency chat while retaining strong general intelligence. It uses adaptive reasoning to selectively “think” on...