DeepSeek V3.5
DeepSeek · released 2025-12-01
Quality (AA Index)81
Input price$0.14
Output price$0.28
Context128K
Throughput95 tok/s
P50 latency1.5s
DeepSeek V3.5 vs GPT-5
Side-by-side pricing, capabilities, real-world cost across common scenarios, and our editorial pick.
Add a modelUp to 4 models can be compared
all prices in USD per 1M tokens
GPT-5
OpenAI · released 2026-01-15
Quality (AA Index)91
Input price$1.25
Output price$10.00
Context400K
Throughput120 tok/s
P50 latency0.7s
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Head-to-head specs
Green column = winner per metric| Metric | DeepSeek V3.5 | GPT-5 | Verdict |
|---|---|---|---|
Input price /1M tokens | $0.14 | $1.25 | DeepSeek V3.5 −89% |
Output price /1M tokens | $0.28 | $10.00 | DeepSeek V3.5 −97% |
Context window max input length | 128K | 400K | GPT-5 +3.1× |
AA Quality AA Intelligence Index (0–100) | 81 | 91 | GPT-5 +10pt |
Arena Elo LMArena human-pref Elo (800–2000) | — | — | Tied |
Throughput tokens per second | 95 | 120 | GPT-5 +26% |
P50 latency first token | 1.5s | 0.7s | GPT-5 −53% |
Vision multimodal | — | ||
Function calling tool use | Tied | ||
Reasoning mode chain-of-thought | — |
Monthly cost across common scenarios
Default usage assumptions| Scenario | DeepSeek V3.5 | GPT-5 |
|---|---|---|
customer support 1000K req · 600/180 tok | $134 | $2.5K |
chat with docs 300K req · 4000/300 tok | $193 | $2.4K |
code generation 500K req · 2000/500 tok | $210 | $3.8K |
voice assistant 600K req · 800/200 tok | $101 | $1.8K |
Our pick
For most workloads, choose GPT-5.
- 3.1× the context window — better for long documents and agents
- 26% faster throughput — matters for streaming UX and voice agents
Best across-the-board quality but the most expensive token rate in the table; pick GPT-5 when reasoning depth or function-calling reliability outranks per-million-token spend.
Choose DeepSeek V3.5 instead if: Roughly GPT-4o-class quality at roughly 90% off. Tradeoff is region availability (Chinese provider) and slower output throughput than Western frontier tiers.
Read our deep analysis
Why pick? Use both with smart routing
Phase 2 · gateway with fallback chainSet GPT-5 as primary, DeepSeek V3.5 as fallback. One key, one bill, automatic failover when GPT-5 errors.
PHASE 2 PREVIEW · gateway not live yetThis endpoint does not exist yet. The gateway is in Phase 2 — what you see below is a design preview of the planned interface, not a live API. We will email subscribers when it launches.
Preview the planned API call
$ curl https://api.aipricly.com/v1/chat/completions \
-H "Authorization: Bearer $AIPC_KEY" \
-d '{
"routing": {
"primary": "openai/gpt-5",
"fallback": ["deepseek/deepseek-v3-5"]
},
"messages": [{"role": "user", "content": "..."}]
}'