Which is cheaper, Gemini 2.5 Flash or GPT-5?

Gemini 2.5 Flash is cheaper at the input + output rate combined: $2.80 versus $11.25 per million tokens.

Which has higher quality, Gemini 2.5 Flash or GPT-5?

GPT-5 has the higher AA Intelligence Index score: 91 versus 78.

Can I switch between Gemini 2.5 Flash and GPT-5 via one API?

Both Gemini 2.5 Flash and GPT-5 are accessible through OpenRouter's unified gateway, which lets you switch models with one API key. Phase 2 of AIpricly will add scenario-routed automatic primary + fallback chains.

Gemini 2.5 Flash 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

OVERALL WINNER

Gemini 2.5 Flash

Google · released 2025-09-01

Quality (AA Index)78

Input price$0.30

Output price$2.50

Context1M

Throughput320 tok/s

P50 latency0.3s

View full pricing

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

View full pricing

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Head-to-head specs

Green column = winner per metric

Metric	Gemini 2.5 Flash	GPT-5	Verdict
Input price /1M tokens	$0.30	$1.25	Gemini 2.5 Flash −76%
Output price /1M tokens	$2.50	$10.00	Gemini 2.5 Flash −75%
Context window max input length	1M	400K	Gemini 2.5 Flash +2.5×
AA Quality AA Intelligence Index (0–100)	78	91	GPT-5 +13pt
Arena Elo LMArena human-pref Elo (800–2000)	—	—	Tied
Throughput tokens per second	320	120	Gemini 2.5 Flash +167%
P50 latency first token	0.3s	0.7s	Gemini 2.5 Flash −57%
Vision multimodal			Tied
Function calling tool use			Tied
Reasoning mode chain-of-thought			Tied

Monthly cost across common scenarios

Default usage assumptions

Scenario	Gemini 2.5 Flash	GPT-5
customer support 1000K req · 600/180 tok	$630	$2.5K
chat with docs 300K req · 4000/300 tok	$585	$2.4K
code generation 500K req · 2000/500 tok	$925	$3.8K
voice assistant 600K req · 800/200 tok	$444	$1.8K

Our pick

For most workloads, choose Gemini 2.5 Flash.

76% cheaper input price, which compounds at scale
2.5× the context window — better for long documents and agents
167% faster throughput — matters for streaming UX and voice agents

The price-performance benchmark for vision tasks. Strong multimodal, weak on deep reasoning. Pair as a fast first hop ahead of a smarter fallback.

Choose GPT-5 instead if: 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.

Read our deep analysis

Why pick? Use both with smart routing

Phase 2 · gateway with fallback chain

Set Gemini 2.5 Flash as primary, GPT-5 as fallback. One key, one bill, automatic failover when Gemini 2.5 Flash 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-flash",
      "fallback": ["openai/gpt-5"]
    },
    "messages": [{"role": "user", "content": "..."}]
  }'