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Claude Opus 4.5 vs GPT OSS 120B (Cerebras): API Cost Comparison

Compare the API pricing, context windows, features, and real-world cost projections for Claude Opus 4.5 (Anthropic) and GPT OSS 120B (Cerebras) (Cerebras). Use the interactive calculator below to compute your exact monthly cost based on your token usage and request volume.

Prices verified Mar 24, 2026

Interactive Cost Calculator

AnthropicClaude Opus 4.5CerebrasGPT OSS 120B (Cerebras)

Fills in typical token counts for a workload type

Tokens in each prompt sent to the model

Tokens generated in each response

Total API calls per month

Showing costs for 2 models. Cheapest: GPT OSS 120B (Cerebras) at $7.25/month.

Cheapest: GPT OSS 120B (Cerebras) at $7.25/mo — save 95.9% vs Claude Opus 4.5
Alert
BestGPT OSS 120B (Cerebras)
Cerebras$7.25$0.000725$3.50$3.7595.9%Alerts coming soon
Claude Opus 4.5
Anthropic$175.00$0.017500$50.00$125.00Alerts coming soon

Monthly Cost Comparison

Price Comparison at a Glance

All prices are in USD per 1 million tokens ($/M tokens). Lower is cheaper.

Pricing TypeClaude Opus 4.5GPT OSS 120B (Cerebras)Cheaper
Input (standard)$5.00/M$0.35/MGPT OSS 120B (Cerebras)
Output$25.00/M$0.75/MGPT OSS 120B (Cerebras)
Cached input$0.50/MN/A
Batch input$2.50/MN/A
Batch output$12.50/MN/A

Prices last verified: 2026-03-10 – 2026-03-24

Cost Breakdown by Usage Volume

Estimated monthly costs at different request volumes, assuming 1,000 input tokens and 500 output tokens per request. Adjust in the calculator above for your specific use case.

VolumeClaude Opus 4.5MonthlyGPT OSS 120B (Cerebras)MonthlyClaude Opus 4.5Per requestGPT OSS 120B (Cerebras)Per request
1K requests/mo$17.50$0.72$0.017500$0.000725
10K requests/mo$175.00$7.25$0.017500$0.000725
100K requests/mo$1,750.00$72.50$0.017500$0.000725
1M requests/mo$17,500.00$725.00$0.017500$0.000725

Green values indicate the lower-cost option at each volume tier. Cost per request is calculated at 1,000 input + 500 output tokens using standard (non-batch, non-cached) pricing.

Price History

Input price per 1M tokens

When to Choose Claude Opus 4.5

by Anthropic

  • Code generation
  • Document summarization
  • RAG / Semantic search

Input / 1M tokens

$5.00/M

Output / 1M tokens

$25.00/M

Context window

200,000

Tier

premium

When to Choose GPT OSS 120B (Cerebras)

by Cerebras

  • Code generation
  • Document summarization
  • General chatbot

Input / 1M tokens

$0.35/M

Output / 1M tokens

$0.75/M

Context window

128,000

Tier

mid

Key Differences Beyond Price

Cost is only one factor in choosing an AI model. Context window size, rate limits, supported features, and latency all affect whether a model fits your use case.

CapabilityClaude Opus 4.5GPT OSS 120B (Cerebras)
Context window200,000 tokens128,000 tokens
Max output tokens64,000 tokens16,384 tokens
Performance tierPremiumMid
Vision / image inputYesNo
Function callingYesYes
JSON modeYesYes
Prompt cachingYesNo
Batch API (50% discount)YesNo
Extended reasoningYesNo
Fine-tuningNoNo
Rate limit (req/min)4,000Not published

Claude Opus 4.5 notes

Extended thinking available. Prompt caching reduces cost by up to 90%.

GPT OSS 120B (Cerebras) notes

Cerebras wafer-scale inference: ~3,000 tokens/sec. Best for latency-critical production workloads requiring a large model.

Frequently Asked Questions

Is Claude Opus 4.5 cheaper than GPT OSS 120B (Cerebras)?

At standard usage (1,000 input tokens, 500 output tokens, 100,000 requests/month), GPT OSS 120B (Cerebras) costs $72.50/month versus $1,750.00/month for Claude Opus 4.5 — a 96% saving. Your actual savings will vary based on your token profile; output-heavy workloads amplify differences in output pricing.

Which model has a larger context window, Claude Opus 4.5 or GPT OSS 120B (Cerebras)?

Claude Opus 4.5 has a larger context window at 200,000 tokens, compared to 128,000 tokens for GPT OSS 120B (Cerebras). A larger context window is important for processing long documents, multi-turn conversations, or large codebases without truncation.

Do Claude Opus 4.5 and GPT OSS 120B (Cerebras) support the Batch API?

Claude Opus 4.5 supports the Batch API (50% discount for async processing), while GPT OSS 120B (Cerebras) does not. If your workload tolerates up to 24-hour latency, routing to Claude Opus 4.5 with batch pricing could significantly cut costs versus GPT OSS 120B (Cerebras)'s standard rate.

Which model offers better prompt caching?

Claude Opus 4.5 supports prompt caching at $0.50/M for cached input, while GPT OSS 120B (Cerebras) does not offer prompt caching. For RAG applications or chatbots with large, repeated context, Claude Opus 4.5's caching capability can substantially reduce effective costs.

What are the best use cases for Claude Opus 4.5 vs GPT OSS 120B (Cerebras)?

Both models are well-suited for Code generation, Document summarization. Claude Opus 4.5 is particularly strong for RAG / Semantic search. GPT OSS 120B (Cerebras) is favored for General chatbot. At the same quality level, the lower-cost model is usually preferable; use this page's calculator to compare total monthly spend at your volume.

What is the cost per request for Claude Opus 4.5 vs GPT OSS 120B (Cerebras)?

At 1,000 input tokens and 500 output tokens per request — a typical conversational workload — Claude Opus 4.5 costs $0.017500 per request and GPT OSS 120B (Cerebras) costs $0.000725 per request. At 100,000 requests/month, that translates to $1,750.00 and $72.50 respectively. Use the interactive calculator to adjust these parameters for your actual workload.

Claude Opus 4.5 vs GPT OSS 120B (Cerebras): Summary

When comparing Claude Opus 4.5 and GPT OSS 120B (Cerebras) for API cost, the right choice depends on your workload's token profile, required features, and tolerance for latency. GPT OSS 120B (Cerebras) offers lower total cost at standard usage volumes (1,000 input + 500 output tokens per request at 100,000 requests/month) at $72.50/month, compared to $1,750.00/month for Claude Opus 4.5.

Both models are priced in USD per million tokens, the standard unit across all major AI API providers. Claude Opus 4.5 charges $5.00/M for input tokens and $25.00/M for output tokens. GPT OSS 120B (Cerebras) charges $0.35/M input and $0.75/M output. If your workload is output-heavy (more tokens generated than consumed as input), the model with the lower output price compounds cost savings significantly at scale.

Prompt caching is supported by Claude Opus 4.5 but not GPT OSS 120B (Cerebras). For workloads with large, repeated system prompts or document context — such as RAG pipelines or multi-turn conversations with a fixed knowledge base — prompt caching can reduce effective input costs by 60–90%, which may change the cost ranking between these two models at your specific usage pattern.

Context window capacity differs between the two: Claude Opus 4.5 supports up to 200,000 tokens in a single request, versus 128,000 tokens for GPT OSS 120B (Cerebras). A larger context window is essential for document summarization, large codebase analysis, and multi-document retrieval-augmented generation (RAG) applications.

Use the interactive calculator at the top of this page to enter your actual token usage and monthly request volume for a precise cost comparison tailored to your workload. Adjust for batch API discounts and prompt caching to find the most cost-effective option for your specific deployment.

Explore other model comparisons from the same providers or performance tiers.

Related Provider Pages

View complete pricing tables and model lineups for the providers behind these models.

Relevant Use Cases

See cost recommendations for workloads where Claude Opus 4.5 or GPT OSS 120B (Cerebras) is recommended.