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Gemini 2.5 Flash vs Grok 4.3: pricing and benchmarks

Gemini 2.5 Flash is 76% cheaper on input tokens ($0.30 vs $1.25 per 1M). Both charge $2.50 per 1M output tokens. On our document Q&A workload (50,000 questions a month), Gemini 2.5 Flash costs $195.00 a month versus $575.00 for Grok 4.3, 66% less. Epoch AI has not published a capability index score for Grok 4.3 yet.

Prices verified September 14, 2026.

Which should you choose?

Overall capability
Too close to call

Epoch AI has not published a capability index score for Grok 4.3 yet.

Price
Gemini 2.5 Flash

Gemini 2.5 Flash costs $0.85 per 1M tokens (3:1 input-to-output mix) vs $1.563 for Grok 4.3, 46% less.

Pricing and specs

Gemini 2.5 FlashGrok 4.3
ProviderGooglexAI
API model IDgemini-2.5-flashgrok-4.3
Input / 1M tokens$0.30$1.25
Cached input / 1M tokens$0.03$0.20
Output / 1M tokens$2.50$2.50
Long-context rates$2.50 in / $5.00 out above 200K prompt tokens
Context window1.05M tokens1M tokens
Max output66K tokens
Batch discount

Benchmarks

Gemini 2.5 FlashGrok 4.3
Epoch Capabilities Index140.5
GPQA Diamond· Science reasoning
FrontierMath (Tiers 1–3)· Advanced math
SimpleQA Verified· Factual accuracy
ARC-AGI-2· Abstract reasoning
DeepSWE· Coding
APEX-Agents· Agentic work1.8%

Source: Epoch AI, best recorded result per model (CC BY 4.0). A dash means no published score. See all benchmarks

Monthly cost for real workloads

WorkloadGemini 2.5 FlashGrok 4.3Difference
Support chatbot
100,000 replies a month, ~1,500 input tokens (system prompt + history) and ~400 output tokens each.
$145.00$287.50Gemini 2.5 Flash 50% cheaper
Document Q&A (RAG)
50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each.
$195.00$575.00Gemini 2.5 Flash 66% cheaper
Coding agent
10,000 agent steps a month, ~40,000 input tokens each (70% read from the prompt cache) and ~2,000 output tokens.
$94.40$256.00Gemini 2.5 Flash 63% cheaper

Estimates use standard list prices and ignore cache-write surcharges. Different tokenizers can count the same text differently, so test with your own prompts.

Gemini 2.5 Flash vs Grok 4.3 cost calculator

Standard-tier list prices. Long-context rates apply automatically where the provider publishes a threshold. Excludes cache-write surcharges, taxes, batch and volume discounts.

Gemini 2.5 Flash pricing notes

Google’s previous-generation Flash model.

  • Audio input costs $1.00 per 1M tokens; text, image and video cost $0.30.
  • Output price includes thinking tokens.
Google official pricing ↗

Grok 4.3 pricing notes

An earlier Grok 4 model with a 1M-token context window.

  • Requests with 200K or more prompt tokens are billed at $2.50 input / $0.40 cached / $5 output for all tokens.
xAI official pricing ↗

Frequently asked questions

Is Gemini 2.5 Flash cheaper than Grok 4.3?
Gemini 2.5 Flash is 76% cheaper on input tokens ($0.30 vs $1.25 per 1M). Both charge $2.50 per 1M output tokens. On our document Q&A workload (50,000 questions a month), Gemini 2.5 Flash costs $195.00 a month versus $575.00 for Grok 4.3, 66% less.
Which is more capable, Gemini 2.5 Flash or Grok 4.3?
Epoch AI has not published a capability index score for Grok 4.3 yet.
How much does Gemini 2.5 Flash cost per 1M tokens?
Gemini 2.5 Flash costs $0.30 per 1M input tokens and $2.50 per 1M output tokens, and $0.03 per 1M cached input tokens on Google’s standard tier.
How much does Grok 4.3 cost per 1M tokens?
Grok 4.3 costs $1.25 per 1M input tokens and $2.50 per 1M output tokens, and $0.20 per 1M cached input tokens on xAI’s standard tier.
Which has the larger context window, Gemini 2.5 Flash or Grok 4.3?
Gemini 2.5 Flash has the larger context window: 1.05M tokens versus 1M for Grok 4.3.

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