# Claude Sonnet 5.5 vs DeepSeek V4 Pro

DeepSeek V4 Pro is the cheaper of the 2: for the same tokens, 3 read for each 1 written, Claude Sonnet 5.5 costs 2 times as much. Below are both price lists, what 8 everyday jobs cost a month on each, and how many tokens the same text takes on each, which can change the answer.

- Page, with a calculator for your own job: https://tecyfy.com/prices/compare/claude-sonnet-5-5-vs-deepseek-v4-pro
- Makers: Claude Sonnet 5.5 from Anthropic, DeepSeek V4 Pro from DeepSeek

## Price per million tokens, in US dollars

| | Claude Sonnet 5.5 | DeepSeek V4 Pro |
| --- | --: | --: |
| Input | $2 | $1.32 |
| Cached input | $0.10 | $0.044 |
| Cache write | $2.50 | not listed |
| Output | $10 | $3.96 |
| Blend, 3 read for each 1 written | $4 | $1.98 |
| Batch input | $1 | not listed |
| Batch output | $5 | not listed |
| Context window, tokens | 1M | 1M |
| Capability score (Epoch Capabilities Index; GPT-5 is 150) | 164 | 155 |
| Longest answer, tokens | 128K | not listed |

DeepSeek V4 Pro: The peak-hours price. Off-peak hours are half. Peak is 01:00 to 04:00 and 06:00 to 10:00 UTC on weekdays.

Price change, Claude Sonnet 5.5: Cached input went from $0.20 to $0.10 per million tokens. The price of a cache write did not change.

## The same text, counted by each maker

Our lesson "How AI writes" (https://tecyfy.com/learn/how-ai-works/how-ai-writes), about 1,700 words of English:

- Claude Sonnet 5.5: about 2,100 to 3,600 tokens. Anthropic does not publish its tokenizer. It says Claude 4.7 and later produce about 30 percent more tokens for the same text than earlier models, and an independent test counted TypeScript at 1.73 times OpenAI's figure. The range runs from OpenAI's count to 1.75 times it.
- DeepSeek V4 Pro: 2,063 tokens. Counted with the tokenizer DeepSeek publishes with V4-Pro and V4.1 Flash, the same models its API serves.

## What 8 everyday jobs cost a month on each

Each job at its usual runs a day, for 30 days, at the standard price.

| Job | Tokens in, out, runs a day | Claude Sonnet 5.5 | DeepSeek V4 Pro |
| --- | --- | --: | --: |
| A chat question | 300, 500, 100 | $16.80 | $7.13 |
| A hard question, with thinking | 300, 1,400, 100 | $43.80 | $17.82 |
| A long report, summarised | 60,000, 2,000, 20 | $84.00 | $52.27 |
| A 40-turn agent task | 2,800,000, 40,000, 10 | $364 | $192 |
| A support bot's reply | 4,000, 300, 2,000 | $432 | $235 |
| Sort a message into a category | 250, 5, 50,000 | $825 | $525 |
| Read an invoice into fields | 1,500, 250, 1,000 | $165 | $89.10 |
| Review a pull request | 25,000, 4,500, 50 | $143 | $76.23 |

## Questions

### Which is cheaper, Claude Sonnet 5.5 or DeepSeek V4 Pro?

DeepSeek V4 Pro is cheaper: $1.32 per million tokens read and $3.96 per million written, against $2 and $10 on Claude Sonnet 5.5. On a mix of 3 tokens read for each 1 written, Claude Sonnet 5.5 costs 2 times as much.

### Which is better, Claude Sonnet 5.5 or DeepSeek V4 Pro?

On the Epoch Capabilities Index, an independent score from Epoch AI that combines over 50 benchmarks, Claude Sonnet 5.5 scores 164 and DeepSeek V4 Pro 155, above the top of the range of doubt around DeepSeek V4 Pro's score (GPT-5 is 150). One score is an average; test both on your own work before you switch.

### What does a support bot cost a month on Claude Sonnet 5.5 and DeepSeek V4 Pro?

At 2,000 replies a day, each reading 4,000 tokens (50 percent of them from cache) and writing 300, it costs $432 a month on Claude Sonnet 5.5 and $235 on DeepSeek V4 Pro: Claude Sonnet 5.5 costs 1.8 times as much for this job.

### What does an AI agent task cost on Claude Sonnet 5.5 and DeepSeek V4 Pro?

One 40-turn task that reads 2,800,000 tokens in all, 90 percent of them from cache, and writes 40,000, costs $1.21 on Claude Sonnet 5.5 and 64 cents on DeepSeek V4 Pro. At 10 tasks a day that is $364 and $192 a month.

### Which has the larger context window, Claude Sonnet 5.5 or DeepSeek V4 Pro?

Neither: both hold 1M tokens at once, about 1,500 pages of English text.

### Does the same text take the same number of tokens on Claude Sonnet 5.5 and DeepSeek V4 Pro?

No. Our lesson "How AI writes", 1,700 words long, is about 2,100 to 3,600 tokens on Claude Sonnet 5.5 and 2,063 on DeepSeek V4 Pro. Each maker cuts text its own way, and every extra token is paid for at the model's price.

### Can I pay less on Claude Sonnet 5.5 and DeepSeek V4 Pro for work that can wait?

On Claude Sonnet 5.5 only: with a batch, where you collect the answers later, it costs $1 per million tokens read and $5 written. DeepSeek's price page lists no batch price for DeepSeek V4 Pro.

## Sources

- [Anthropic: API prices](https://platform.claude.com/docs/en/about-claude/pricing)
- [DeepSeek: API prices](https://api-docs.deepseek.com/quick_start/pricing)
- [Epoch Capabilities Index, by Epoch AI (CC BY 4.0)](https://epoch.ai/benchmarks/eci)

## Other comparisons

- [Claude Mythos 5.1 vs Claude Sonnet 5.5](https://tecyfy.com/prices/compare/claude-mythos-5-1-vs-claude-sonnet-5-5.md)
- [Claude Fable 5 vs Claude Sonnet 5.5](https://tecyfy.com/prices/compare/claude-fable-5-vs-claude-sonnet-5-5.md)
- [Claude Mythos 5 vs Claude Sonnet 5.5](https://tecyfy.com/prices/compare/claude-mythos-5-vs-claude-sonnet-5-5.md)
- [Claude Opus 5 vs Claude Sonnet 5.5](https://tecyfy.com/prices/compare/claude-opus-5-vs-claude-sonnet-5-5.md)
- [Claude Opus 4.8 vs Claude Sonnet 5.5](https://tecyfy.com/prices/compare/claude-opus-4-8-vs-claude-sonnet-5-5.md)
- [Claude Opus 4.7 vs Claude Sonnet 5.5](https://tecyfy.com/prices/compare/claude-opus-4-7-vs-claude-sonnet-5-5.md)