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DeepSeek V3.1 (Together AI) vs GPT OSS 120B (Fireworks): API Cost Comparison

Compare the API pricing, context windows, features, and real-world cost projections for DeepSeek V3.1 (Together AI) (Together AI) and GPT OSS 120B (Fireworks) (Fireworks AI). Use the interactive calculator below to compute your exact monthly cost based on your token usage and request volume.

Prices verified Mar 10, 2026

Interactive Cost Calculator

Together AIDeepSeek V3.1 (Together AI)Fireworks AIGPT OSS 120B (Fireworks)

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 (Fireworks) at $4.50/month.

Cheapest: GPT OSS 120B (Fireworks) at $4.50/mo — save 69.0% vs DeepSeek V3.1 (Together AI)
Alert
BestGPT OSS 120B (Fireworks)
Fireworks AI$4.50$0.000450$1.50$3.0069.0%Alerts coming soon
DeepSeek V3.1 (Together AI)
Together AI$14.50$0.001450$6.00$8.50Alerts 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 TypeDeepSeek V3.1 (Together AI)GPT OSS 120B (Fireworks)Cheaper
Input (standard)$0.60/M$0.15/MGPT OSS 120B (Fireworks)
Output$1.70/M$0.60/MGPT OSS 120B (Fireworks)
Cached inputN/A$0.08/M
Batch inputN/A$0.08/M
Batch outputN/A$0.30/M

Prices last verified: 2026-03-06 – 2026-03-10

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.

VolumeDeepSeek V3.1 (Together AI)MonthlyGPT OSS 120B (Fireworks)MonthlyDeepSeek V3.1 (Together AI)Per requestGPT OSS 120B (Fireworks)Per request
1K requests/mo$1.45$0.45$0.001450$0.000450
10K requests/mo$14.50$4.50$0.001450$0.000450
100K requests/mo$145.00$45.00$0.001450$0.000450
1M requests/mo$1,450.00$450.00$0.001450$0.000450

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 DeepSeek V3.1 (Together AI)

by Together AI

  • General chatbot
  • Content & copywriting
  • Code generation

Input / 1M tokens

$0.60/M

Output / 1M tokens

$1.70/M

Context window

65,536

Tier

mid

When to Choose GPT OSS 120B (Fireworks)

by Fireworks AI

  • Code generation
  • Document summarization
  • RAG / Semantic search

Input / 1M tokens

$0.15/M

Output / 1M tokens

$0.60/M

Context window

131,072

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.

CapabilityDeepSeek V3.1 (Together AI)GPT OSS 120B (Fireworks)
Context window65,536 tokens131,072 tokens
Max output tokens8,192 tokens16,384 tokens
Performance tierMidMid
Vision / image inputNoNo
Function callingYesYes
JSON modeYesYes
Prompt cachingNoYes
Batch API (50% discount)NoYes
Extended reasoningNoNo
Fine-tuningNoNo

DeepSeek V3.1 (Together AI) notes

DeepSeek V3.1 via Together AI infrastructure.

GPT OSS 120B (Fireworks) notes

Fireworks serverless pricing. Cached input 50% discount. Batch at 50% of serverless.

Frequently Asked Questions

Is DeepSeek V3.1 (Together AI) cheaper than GPT OSS 120B (Fireworks)?

At standard usage (1,000 input tokens, 500 output tokens, 100,000 requests/month), GPT OSS 120B (Fireworks) costs $45.00/month versus $145.00/month for DeepSeek V3.1 (Together AI) — a 69% 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, DeepSeek V3.1 (Together AI) or GPT OSS 120B (Fireworks)?

GPT OSS 120B (Fireworks) has a larger context window at 131,072 tokens, compared to 65,536 tokens for DeepSeek V3.1 (Together AI). A larger context window is important for processing long documents, multi-turn conversations, or large codebases without truncation.

Do DeepSeek V3.1 (Together AI) and GPT OSS 120B (Fireworks) support the Batch API?

GPT OSS 120B (Fireworks) supports the Batch API (50% discount for async processing), while DeepSeek V3.1 (Together AI) does not. If your workload tolerates up to 24-hour latency, routing to GPT OSS 120B (Fireworks) with batch pricing could significantly cut costs versus DeepSeek V3.1 (Together AI)'s standard rate.

Which model offers better prompt caching?

GPT OSS 120B (Fireworks) supports prompt caching at $0.08/M for cached input, while DeepSeek V3.1 (Together AI) does not offer prompt caching. For RAG applications or chatbots with large, repeated context, GPT OSS 120B (Fireworks)'s caching capability can substantially reduce effective costs.

What are the best use cases for DeepSeek V3.1 (Together AI) vs GPT OSS 120B (Fireworks)?

Both models are well-suited for Code generation. DeepSeek V3.1 (Together AI) is particularly strong for General chatbot, Content & copywriting. GPT OSS 120B (Fireworks) is favored for Document summarization, RAG / Semantic search. 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 DeepSeek V3.1 (Together AI) vs GPT OSS 120B (Fireworks)?

At 1,000 input tokens and 500 output tokens per request — a typical conversational workload — DeepSeek V3.1 (Together AI) costs $0.001450 per request and GPT OSS 120B (Fireworks) costs $0.000450 per request. At 100,000 requests/month, that translates to $145.00 and $45.00 respectively. Use the interactive calculator to adjust these parameters for your actual workload.

DeepSeek V3.1 (Together AI) vs GPT OSS 120B (Fireworks): Summary

When comparing DeepSeek V3.1 (Together AI) and GPT OSS 120B (Fireworks) for API cost, the right choice depends on your workload's token profile, required features, and tolerance for latency. GPT OSS 120B (Fireworks) offers lower total cost at standard usage volumes (1,000 input + 500 output tokens per request at 100,000 requests/month) at $45.00/month, compared to $145.00/month for DeepSeek V3.1 (Together AI).

Both models are priced in USD per million tokens, the standard unit across all major AI API providers. DeepSeek V3.1 (Together AI) charges $0.60/M for input tokens and $1.70/M for output tokens. GPT OSS 120B (Fireworks) charges $0.15/M input and $0.60/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 GPT OSS 120B (Fireworks) but not DeepSeek V3.1 (Together AI). 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: GPT OSS 120B (Fireworks) supports up to 131,072 tokens in a single request, versus 65,536 tokens for DeepSeek V3.1 (Together AI). 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

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Relevant Use Cases

See cost recommendations for workloads where DeepSeek V3.1 (Together AI) or GPT OSS 120B (Fireworks) is recommended.