Claude Sonnet 5.5 vs DeepSeek V3.1 Terminus
Pick up to 3 models · pricing, context and capabilities · simulate your product cost
Data updated on September 30, 2026· 217 models
Claude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade.
- Reasoning estimated
- Speed estimated
- Input
- Output
- Context
- ▲1 M tokens
- Max output
- ▲128 K
- Input, $ per 1M tokens
- $2.00
- Output, $ per 1M tokens
- $10.00
- Cache read, $ per 1M
- $0.200
- Batch (input / output)
- $1.00 / $5.00
- Tool calling
- Yes
- Released
- ▲09/28/2026
- Knowledge cutoff
- 2026-06
- API id
- anthropic/claude-sonnet-5.5
DeepSeek-V3.1 Terminus is an update to DeepSeek V3.1 that maintains the model's original capabilities while addressing issues reported by users, including language consistency and agent capabilities, further optimizing the model's...
- Reasoning estimated
- Speed estimated
- Input
- Output
- Context
- 164 K tokens
- Max output
- 66 K
- Input, $ per 1M tokens
- ▲$0.300
- Output, $ per 1M tokens
- ▲$1.00
- Cache read, $ per 1M
- $0.135
- Batch (input / output)
- —
- Tool calling
- Yes
- Released
- 09/22/2025
- Knowledge cutoff
- 2025-09
- API id
- deepseek/deepseek-v3.1-terminus
Which is the better API choice: Claude Sonnet 5.5 vs DeepSeek V3.1 Terminus?
- DeepSeek V3.1 Terminus: cheapest input (85% less than Claude Sonnet 5.5)
- DeepSeek V3.1 Terminus: cheapest output
- Claude Sonnet 5.5: largest context (1 M)
- Claude Sonnet 5.5: the newest (09/28/2026)
DeepSeek V3.1 Terminus costs 85% less on input and 90% less on output than Claude Sonnet 5.5 ($0.300 / $1.00 versus $2.00 / $10.00 per million tokens). Claude Sonnet 5.5 accepts more context (1 M). On capabilities, Claude Sonnet 5.5 accepts images. Claude Sonnet 5.5 offers a batch tier at half price for jobs that do not need an immediate answer.
What would your product cost?
Estimate the monthly cost with your app's real volume. List prices, no cache or batch discounts.
With DeepSeek V3.1 Terminus you save $61.50 a month versus Claude Sonnet 5.5 (88% less).
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- 3Qwen3.7 Flash Qwen$0.97
- 4DeepSeek V4 Flash 0731 DeepSeek$1.55
- 5Ministral 3 3B 2512 Mistral$1.90
- 6Qwen3.5-Flash Qwen$2.02
Paste your prompt: tokens and cost per model
Rough estimate (about 4 characters per token). Nothing is sent to any server.
Cost of sending it 1,000 times (input only)
- 1DeepSeek V3.1 Terminus DeepSeek$0.023
- 2Claude Sonnet 5.5 Anthropic$0.152
- 3Claude Sonnet 5 Anthropic$0.152
- 4Claude Opus 5.5 Anthropic$0.304
- 5Claude Opus 5 Anthropic$0.380
- 6Claude Opus 4.8 Anthropic$0.380
- 7Claude Fable 5.1 Anthropic$0.760
- 8Claude Fable 5 Anthropic$0.760
Popular comparisons
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- GPT-6.1 Sol vs Gemini 3.8 Flash
- GPT-6.1 Sol vs DeepSeek V4.1 Flash
- GPT-6.1 Sol vs Grok 4.7
- Gemini 3.8 Flash vs DeepSeek V4.1 Flash
- Gemini 3.8 Flash vs Grok 4.7
- DeepSeek V4.1 Flash vs Grok 4.7
Frequently asked questions
Which is the better API choice: Claude Sonnet 5.5 vs DeepSeek V3.1 Terminus?
DeepSeek V3.1 Terminus costs 85% less on input and 90% less on output than Claude Sonnet 5.5 ($0.300 / $1.00 versus $2.00 / $10.00 per million tokens). Claude Sonnet 5.5 accepts more context (1 M). On capabilities, Claude Sonnet 5.5 accepts images. Claude Sonnet 5.5 offers a batch tier at half price for jobs that do not need an immediate answer.
Which is cheaper: Claude Sonnet 5.5 and DeepSeek V3.1 Terminus?
DeepSeek V3.1 Terminus is cheaper: $0.300 per million input tokens and $1.00 per million output tokens, versus $2.00 / $10.00 for Claude Sonnet 5.5.
Which has more context: Claude Sonnet 5.5 and DeepSeek V3.1 Terminus?
Claude Sonnet 5.5 accepts 1 M tokens of context; DeepSeek V3.1 Terminus accepts 164 K.
Which is newer: Claude Sonnet 5.5 and DeepSeek V3.1 Terminus?
Claude Sonnet 5.5 was released on 09/28/2026; DeepSeek V3.1 Terminus on 09/22/2025.
What would 10,000 requests a month cost with Claude Sonnet 5.5 and DeepSeek V3.1 Terminus?
With 1,500 input and 400 output tokens per request: Claude Sonnet 5.5: $70.00; DeepSeek V3.1 Terminus: $8.50 a month, at list price.
Where do the prices come from and how often are they updated?
From the public catalogs of OpenRouter, models.dev and LiteLLM, which publish each provider's list prices. They sync once a day and the last update date is shown above the comparison.
What does price per million tokens mean?
It is what the provider charges per million tokens you send (input) or the model generates (output). A token is roughly 4 characters. Output almost always costs more than input.
Sources: OpenRouter, models.dev and LiteLLM. Prices in USD per million tokens, list price, no volume discounts. Prompt tokens are an estimate; each provider's tokenizer may differ.