Claude Sonnet 5 vs DeepSeek-V4-Flash-0731: Specs & Benchmark Comparison

Claude Sonnet 5 is developed by Anthropic, while DeepSeek-V4-Flash-0731 comes from DeepSeek. Claude Sonnet 5 was released in June 2026, and DeepSeek-V4-Flash-0731 followed a month later in July 2026. DeepSeek-V4-Flash-0731 has a published size of about 304 billion parameters; Anthropic has not disclosed the parameter count of Claude Sonnet 5.

The two models share 2 published benchmarks. DeepSeek-V4-Flash-0731 leads on 2 of them. The widest gaps are on Toolathlon, where DeepSeek-V4-Flash-0731 scores 70.0% against 54.3%; AutomationBench, where DeepSeek-V4-Flash-0731 scores 25.1% against 13.5%. Averaged across everything we track, Claude Sonnet 5 sits at 58.4% and DeepSeek-V4-Flash-0731 at 57.5%.

DeepSeek-V4-Flash-0731 is the cheaper API at $0.14 per million input tokens and $0.28 per million output tokens, roughly 14 times cheaper than Claude Sonnet 5 at $2 and $10. Both accept a context window of about 1M tokens. Claude Sonnet 5 accepts text and images as input, while DeepSeek-V4-Flash-0731 accepts text.

CharacteristicClaude Sonnet 5DeepSeek-V4-Flash-0731
CompanyAnthropicDeepSeek
Release DateJune 30, 2026July 31, 2026
Parameters304B
MultimodalYesNo
Context (input)1.0M1.0M
Context (output)64K393K
Input Price / 1M$2.00$0.14
Output Price / 1M$10.00$0.28
Average Score58.4%57.5%
Benchmarks
Toolathlon54.3%70.0%
AutomationBench13.5%25.1%

Visual Benchmark Comparison

Claude Sonnet 5
DeepSeek-V4-Flash-0731
Toolathlon0.5 vs 0.7
0.5
0.7
AutomationBench0.1 vs 0.3
0.1
0.3

Verdict

DeepSeek-V4-Flash-0731 leads in 2 out of 4 comparison categories.

Overall Performance

Both models show comparable average scores: Claude Sonnet 5 — 0.6, DeepSeek-V4-Flash-0731 — 0.6.

API Cost

DeepSeek-V4-Flash-0731 is 28.6x cheaper: input $0.14/1M vs $2.00/1M tokens.

Context Window

Same context size: 1M tokens.

Recency

DeepSeek-V4-Flash-0731 is newer: released 7/31/2026 vs 6/30/2026.

More About These Models

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Frequently Asked Questions

Which is better for coding — Claude Sonnet 5 or DeepSeek-V4-Flash-0731?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — Claude Sonnet 5 or DeepSeek-V4-Flash-0731?
DeepSeek-V4-Flash-0731 is cheaper for input: $0.14 per 1M tokens vs $2.00.
Which has a larger context window — Claude Sonnet 5 or DeepSeek-V4-Flash-0731?
Claude Sonnet 5 supports a larger context: 1,000,000 tokens vs 1,000,000.

The Claude Sonnet 5 and DeepSeek-V4-Flash-0731 comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Claude Sonnet 5 or DeepSeek-V4-Flash-0731 page. See also the complete list of AI model comparisons.