API cost decision in 10 seconds

GPT Audio vs GPT-5.1-Codex

Pick GPT-5.1-Codex when budget and context both matter.

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-Codex when budget and context both matter.

On the standard 1M input plus 500K output workload, GPT-5.1-Codex is estimated at $6.25 vs $7.5 for GPT Audio, saving $1.25 (16.7% lower).

Cost-first pickGPT-5.1-Codex

Context-first pickGPT-5.1-Codex

Sample savings$1.2516.7%

10x traffic gap$12.5

GPT-5.1-Codex is cheaper on the standard workload and also has the larger context window. At 10x that traffic, the same price gap is about $12.5. 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-Codex stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	GPT Audio	GPT-5.1-Codex
Input-heavy / RAG	5M input + 500K output	GPT-5.1-Codex	$17.5	$11.25
Balanced workload	1M input + 1M output	GPT-5.1-Codex	$12.5	$11.25
Output-heavy chatbot	1M input + 5M output	GPT-5.1-Codex	$52.5	$51.25

Cheaper input GPT-5.1-Codex $2.5 vs $1.25 / 1M

GPT-5.1-Codex is $1.25 cheaper per 1M input tokens (50% lower; 2x difference).

Cheaper output Tie $10 vs $10 / 1M

Both models report the same output price at $10 per 1M tokens.

Larger context GPT-5.1-Codex 128K vs 400K

GPT-5.1-Codex has 272K more context (3.12x larger).

Sample workload GPT-5.1-Codex $7.5 vs $6.25

GPT-5.1-Codex is $1.25 cheaper on the standard workload (16.7% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

GPT Audio Calculating… Estimated API cost

GPT-5.1-Codex 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-Codex has the lower input price; both models tie on output price; GPT-5.1-Codex offers the larger context window. For the 1M input plus 500K output sample, GPT-5.1-Codex is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $7.5 for GPT Audio and $6.25 for GPT-5.1-Codex.

Best Fit

Choose GPT Audio when its provider, model quality, latency, or availability is more important than the numeric price/context winner.

Choose GPT-5.1-Codex when you care most about lower input-token price, and larger context window.

Decision Notes

On the standard 1M input plus 500K output workload, GPT-5.1-Codex is estimated at $6.25 vs $7.5 for GPT Audio, saving $1.25 (16.7% lower).
GPT-5.1-Codex is $1.25 cheaper on the standard workload (16.7% lower).
GPT-5.1-Codex is $1.25 cheaper per 1M input tokens (50% lower; 2x difference).
Both models report the same output price at $10 per 1M tokens.
GPT-5.1-Codex has 272K more context (3.12x larger).

Head-to-Head Specs

Feature	GPT Audio (OpenAI)	GPT-5.1-Codex (OpenAI)
Input Price prompt tokens per 1M	$2.5	$1.25
Completion Price per 1M tokens	$10	$10
Sample Workload Cost 1M input + 500K output	$7.5	$6.25
Context Window	128K	400K
Release Date	2026-01-19	2025-11-13

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	GPT-5.1-Codex	On the standard 1M input plus 500K output workload, GPT-5.1-Codex is estimated at $6.25 vs $7.5 for GPT Audio, saving $1.25 (16.7% lower).
High-volume input processing	GPT-5.1-Codex	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Tie	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	GPT-5.1-Codex	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 GPT Audio when lower sample workload cost matters most: $0.
gpt-oss-20b (free) can replace GPT Audio when lower sample workload cost matters most: $0.
gpt-oss-20b can replace GPT Audio when lower sample workload cost matters most: $0.1.
gpt-oss-120b can replace GPT Audio 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.
Owl Alpha offers 1.05M context with $0 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.

Open cheapest models

Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

Open largest context models

Provider catalogs

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OpenAI catalog

Review all tracked OpenAI models before deciding whether this matchup is the right shortlist.

Open OpenAI models

GPT Audio

The gpt-audio model is OpenAI's first generally available audio model. The new snapshot features an upgraded decoder for more natural sounding voices and maintains better voice consistency. Audio is priced...

GPT-5.1-Codex

GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....