Claude Sonnet 5 vs DeepSeek V3.2
Claude Sonnet 5 and DeepSeek V3.2 sit at opposite ends of the price-performance curve. Sonnet 5 is Anthropic's current Sonnet-class flagship with a 1M-token context window, image and file input, and selectable reasoning effort up to 'max.' DeepSeek V3.2 is a text-only model with sparse attention aimed at efficient reasoning and agentic tool use. Both are available on OpenKey with one API key and a flat 3% fee on top of provider pricing.
Spec vs spec
| Spec | Claude Sonnet 5 | DeepSeek V3.2 |
|---|---|---|
| Context window | 1M | 131K |
| Max output | 128K | 64K |
| Input modalities | text, image, file | text |
| Output modalities | text | text |
| Released | Jun 30, 2026 | Dec 1, 2025 |
| Reasoning | optional | optional |
Pricing
Per 1M tokens. Provider price plus the flat 3% fee — the sum is what you pay.
anthropic/claude-sonnet-5
Input · 1M tokens
$2.00 + 3%$2.06
Output · 1M tokens
$10.00 + 3%$10.30
Cache read · 1M tokens
$0.200 + 3%$0.206
Cache write · 1M tokens
$2.50 + 3%$2.58
FEE — FLAT, EVERY MODEL3%
deepseek/deepseek-v3.2
Input · 1M tokens
$0.229 + 3%$0.236
Output · 1M tokens
$0.343 + 3%$0.353
Cache read · 1M tokens
$0.023 + 3%$0.024
FEE — FLAT, EVERY MODEL3%
One workload, priced on both
10M input + 2M output tokens at each model's price, flat 3% fee included.
anthropic/claude-sonnet-5
$41.20
$40.00 provider + 3%
deepseek/deepseek-v3.2Cheaper
$3.06
$2.97 provider + 3%
Pricing math
Sonnet 5 costs $2.00/M input and $10.00/M output from Anthropic; on OpenKey that's $2.06/M and $10.30/M after the 3% fee ($2.00 x 1.03, $10.00 x 1.03). DeepSeek V3.2 costs $0.2288/M input and $0.3432/M output from DeepSeek, or $0.235664/M and $0.353496/M on OpenKey.
Run the numbers on a 10M-input/2M-output workload: Sonnet 5 costs $40.00, DeepSeek V3.2 costs $2.97. That's a 13.5x gap, driven mostly by input pricing — Sonnet 5's input rate alone is 8.74x DeepSeek V3.2's. If you're processing large batches of text and don't need frontier reasoning, V3.2 changes your unit economics dramatically.
Coding and agentic performance
Sonnet 5 posts an Artificial Analysis coding index of 71.5 and an agentic index of 46.7, with an overall intelligence index of 53.4. These are model-level scores, not head-to-head wins, but they put Sonnet 5 in frontier territory for professional coding and multi-step agent tasks. DeepSeek V3.2 doesn't have Artificial Analysis scores in this dataset; instead it has Design Arena results across categories like codecategories (elo 1213, rank 48), gamedev (elo 1197, rank 50), and website (elo 1217, rank 46) — solid mid-pack results, not top-tier. If coding quality is the bottleneck, not cost, Sonnet 5 is the safer bet.
Context and modality
Sonnet 5 supports a 1,000,000-token context window and up to 128,000 tokens of output; DeepSeek V3.2 supports 131,072 tokens of context and up to 64,000 tokens of output. That's a 7.63x context advantage for Sonnet 5 — relevant if you're feeding it entire codebases, long transcripts, or multi-document research. Sonnet 5 also accepts image and file inputs alongside text; DeepSeek V3.2 is text-only in and out. If your workload involves screenshots, PDFs, or other non-text input, V3.2 is off the table regardless of price.
When to pick each
Pick Sonnet 5 when the task involves images or files, when you need the largest context window available, or when coding/agentic quality is worth paying for. Pick DeepSeek V3.2 when the workload is high-volume text, budget is the binding constraint, and mid-pack Design Arena results (elo in the 1089–1217 range across categories) are good enough. Sonnet 5 also supports adjustable reasoning effort (low through max), giving you a lever to trade latency for quality that V3.2 doesn't expose the same way.
Which model for which job
| Use case | Pick | Why |
|---|---|---|
| Large-scale text summarization pipeline | DeepSeek V3.2 | $2.97 vs $40.00 for a 10M-in/2M-out workload — the cost gap dominates at volume |
| Multimodal analysis (screenshots, PDFs) | Claude Sonnet 5 | DeepSeek V3.2 only accepts text input; Sonnet 5 handles text, image, and file |
| Long-document or full-codebase context | Claude Sonnet 5 | 1,000,000-token context vs 131,072 — a 7.63x window advantage |
| Agentic coding assistant | Claude Sonnet 5 | 71.5 coding index and 46.7 agentic index on Artificial Analysis |
| Budget-constrained high-throughput API calls | DeepSeek V3.2 | Input tokens run $0.235664/M on OpenKey versus $2.06/M for Sonnet 5 |
Questions
- How much cheaper is DeepSeek V3.2 than Claude Sonnet 5?
- On a 10M-input/2M-output workload, DeepSeek V3.2 costs $2.97 versus $40.00 for Claude Sonnet 5 — about 13.5x cheaper. The gap comes mostly from input pricing: Sonnet 5's input rate is 8.74x higher per the computed ratio.
- Which model has a bigger context window?
- Claude Sonnet 5 supports 1,000,000 tokens of context versus 131,072 for DeepSeek V3.2, a 7.63x difference. Sonnet 5 also allows up to 128,000 tokens of output compared to 64,000 for V3.2.
- Can DeepSeek V3.2 handle images or files?
- No. DeepSeek V3.2's modality is text-to-text only. Claude Sonnet 5 accepts text, image, and file inputs, so any workload involving screenshots or documents needs Sonnet 5 or another multimodal model.
- What do the benchmarks actually show?
- Sonnet 5 has an Artificial Analysis coding index of 71.5 and agentic index of 46.7. DeepSeek V3.2 has Design Arena elo scores instead, ranging from 1089 (svg, rank 54) to 1217 (website, rank 46) — the two aren't on the same scale, so treat them as separate signals.