API cost decision in 10 seconds

GPT-5.3-Codex vs NewClaude Opus 4.7 (Fast)

Pick GPT-5.3-Codex for lower cost; pick Claude Opus 4.7 (Fast) only if the larger context window matters more.

Page updated:  Data confirmed:  Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick GPT-5.3-Codex for lower cost; pick Claude Opus 4.7 (Fast) only if the larger context window matters more.

On the standard 1M input plus 500K output workload, GPT-5.3-Codex is estimated at $8.75 vs $105 for Claude Opus 4.7 (Fast), saving $96.25 (91.7% lower).

Cost-first pickGPT-5.3-Codex
Context-first pickClaude Opus 4.7 (Fast)
Sample savings$96.2591.7%
10x traffic gap$962.5

Claude Opus 4.7 (Fast) has more context, but GPT-5.3-Codex saves $96.25 on the standard workload. At 10x that traffic, the same price gap is about $962.5. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

GPT-5.3-Codex stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shapeToken mixBetter pickGPT-5.3-CodexClaude Opus 4.7 (Fast)
Input-heavy / RAG5M input + 500K outputGPT-5.3-Codex$15.75$225
Balanced workload1M input + 1M outputGPT-5.3-Codex$15.75$180
Output-heavy chatbot1M input + 5M outputGPT-5.3-Codex$71.75$780
Cheaper input GPT-5.3-Codex $1.75 vs $30 / 1M

GPT-5.3-Codex is $28.25 cheaper per 1M input tokens (94.2% lower; 17.1x difference).

Cheaper output GPT-5.3-Codex $14 vs $150 / 1M

GPT-5.3-Codex is $136 cheaper per 1M output tokens (90.7% lower; 10.7x difference).

Larger context Claude Opus 4.7 (Fast) 400K vs 1M

Claude Opus 4.7 (Fast) has 600K more context (2.5x larger).

Sample workload GPT-5.3-Codex $8.75 vs $105

GPT-5.3-Codex is $96.25 cheaper on the standard workload (91.7% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
GPT-5.3-Codex Calculating… Estimated API cost
Claude Opus 4.7 (Fast) 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-5.3-Codex has the lower input price; GPT-5.3-Codex has the lower output price; Claude Opus 4.7 (Fast) offers the larger context window. For the 1M input plus 500K output sample, GPT-5.3-Codex is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $8.75 for GPT-5.3-Codex and $105 for Claude Opus 4.7 (Fast).

Best Fit

Choose GPT-5.3-Codex when you care most about lower input-token price, and lower output-token price.

Choose Claude Opus 4.7 (Fast) when you care most about larger context window.

Decision Notes
  • On the standard 1M input plus 500K output workload, GPT-5.3-Codex is estimated at $8.75 vs $105 for Claude Opus 4.7 (Fast), saving $96.25 (91.7% lower).
  • GPT-5.3-Codex is $96.25 cheaper on the standard workload (91.7% lower).
  • GPT-5.3-Codex is $28.25 cheaper per 1M input tokens (94.2% lower; 17.1x difference).
  • GPT-5.3-Codex is $136 cheaper per 1M output tokens (90.7% lower; 10.7x difference).
  • Claude Opus 4.7 (Fast) has 600K more context (2.5x larger).
Head-to-Head Specs
FeatureGPT-5.3-Codex
(OpenAI)		NewClaude Opus 4.7 (Fast)
(Anthropic)
Input Price
prompt tokens per 1M		$1.75$30
Completion Price
per 1M tokens		$14$150
Sample Workload Cost
1M input + 500K output		$8.75$105
Context Window400K1M
Release Date
Popularity#44#112

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productionGPT-5.3-CodexOn the standard 1M input plus 500K output workload, GPT-5.3-Codex is estimated at $8.75 vs $105 for Claude Opus 4.7 (Fast), saving $96.25 (91.7% lower).
High-volume input processingGPT-5.3-CodexLower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsGPT-5.3-CodexLower output-token price matters most when assistants generate many completion tokens.
RAG or long-document workClaude Opus 4.7 (Fast)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-5.3-Codex when lower sample workload cost matters most: $0.
  • gpt-oss-20b (free) can replace GPT-5.3-Codex when lower sample workload cost matters most: $0.
  • gpt-oss-20b can replace GPT-5.3-Codex when lower sample workload cost matters most: $0.1.
  • gpt-oss-120b can replace GPT-5.3-Codex 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 offers 2M context with $2.5 sample workload cost.
  • Grok 4.20 Multi-Agent offers 2M context with $5 sample workload cost.
  • GPT-5.5 offers 1.05M context with $20 sample workload cost.

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.

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Anthropic catalog

Check other Anthropic models with comparable pricing, context, or release timing.

Open Anthropic models
GPT-5.3-Codex

GPT-5.3-Codex is OpenAI’s most advanced agentic coding model, combining the frontier software engineering performance of GPT-5.2-Codex with the broader reasoning and professional knowledge capabilities of GPT-5.2. It achieves state-of-the-art results...

Claude Opus 4.7 (Fast)

Fast-mode variant of [Opus 4.7](/anthropic/claude-opus-4.7) - identical capabilities with higher output speed at premium 6x pricing. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-mode