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DeepSeek V3.5 vs Gemini 2.5 Pro

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

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
View full pricing
OVERALL WINNER

Gemini 2.5 Pro

Google · released 2025-09-01

Quality (AA Index)87
Input price$1.25
Output price$10.00
Context1M
Throughput140 tok/s
P50 latency0.8s
View full pricing
Try DeepSeek V3.5 on OpenRouterTry Gemini 2.5 Pro on OpenRouter

Links open in a new tab via our OpenRouter referral. Affiliate disclosure

Head-to-head specs

Green column = winner per metric
MetricDeepSeek V3.5Gemini 2.5 ProVerdict
Input price
/1M tokens
$0.14$1.25DeepSeek V3.5 −89%
Output price
/1M tokens
$0.28$10.00DeepSeek V3.5 −97%
Context window
max input length
128K1MGemini 2.5 Pro +7.8×
AA Quality
AA Intelligence Index (0–100)
8187Gemini 2.5 Pro +6pt
Arena Elo
LMArena human-pref Elo (800–2000)
——Tied
Throughput
tokens per second
95140Gemini 2.5 Pro +47%
P50 latency
first token
1.5s0.8sGemini 2.5 Pro −47%
Vision
multimodal
—
Function calling
tool use
Tied
Reasoning mode
chain-of-thought
—

Monthly cost across common scenarios

Default usage assumptions
ScenarioDeepSeek V3.5Gemini 2.5 Pro
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 Gemini 2.5 Pro.

  • 7.8× the context window — better for long documents and agents
  • 47% faster throughput — matters for streaming UX and voice agents

Largest context window in the top tier (1M tokens). Tradeoff: pricier than DeepSeek and slower TTFT than GPT-5 — pick when whole-codebase or whole-PDF tasks matter.

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 chain

Set Gemini 2.5 Pro as primary, DeepSeek V3.5 as fallback. One key, one bill, automatic failover when Gemini 2.5 Pro 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": "google/gemini-2-5-pro",
      "fallback": ["deepseek/deepseek-v3-5"]
    },
    "messages": [{"role": "user", "content": "..."}]
  }'

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