Gemini 3.5 Flash vs GPT-5.4
Gemini 3.5 Flash and GPT-5.4 are closely matched at 42.4 and 41.9 on the LLM Stats Score. Gemini 3.5 Flash is 1.7x cheaper per token.
Google · OpenAI · Updated for 2026
Which is better?
Gemini 3.5 Flash and GPT-5.4 are closely matched on the overall LLM Stats Score at 42.4 and 41.9.
In the 12 individual benchmarks reported for both models, Gemini 3.5 Flash wins 8; this is a narrower head-to-head signal than the composite indexes.
On price, Gemini 3.5 Flash is roughly 1.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Gemini 3.5 Flash
- you value its reported benchmark strengths — it wins 8 of 12 exact shared results
- cost matters — it's about 1.7x cheaper per token
- you want the most recent training data — it shipped May 2026
Choose GPT-5.4
- you want predictable pricing at $2.50/M input and $15.00/M output
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
16 reported for Gemini 3.5 Flash · 23 for GPT-5.4
Gemini 3.5 Flash outperforms in 8 benchmarks (Finance Agent, Humanity's Last Exam, Legal Agent Benchmark, MCP Atlas, MMMU-Pro, OSWorld-Verified, Terminal-Bench 2.0, Toolathlon), while GPT-5.4 is better at 4 benchmarks (ARC-AGI v2, DeepSWE 1.1, LiveBench, SWE-Bench Pro).
Gemini 3.5 Flash shows notably better performance in the majority of benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Gemini 3.5 Flash ($1.50/1M tokens) is 1.7x cheaper than GPT-5.4 ($2.50/1M tokens).
For output processing, Gemini 3.5 Flash ($9.00/1M tokens) is 1.7x cheaper than GPT-5.4 ($15.00/1M tokens).
In conclusion, GPT-5.4 is more expensive than Gemini 3.5 Flash.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Both models have the same input context window of 1,000,000 tokens. Gemini 3.5 Flash can generate longer responses up to 1,000,000 tokens, while GPT-5.4 is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Gemini 3.5 Flash and GPT-5.4 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Gemini 3.5 Flash
GPT-5.4
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Gemini 3.5 Flash was released on 2026-05-19, while GPT-5.4 was released on 2026-03-05.
Gemini 3.5 Flash is 3 months newer than GPT-5.4.
May 19, 2026
4 months ago
2mo newerMar 5, 2026
7 months ago
Knowledge Cutoff
When training data ends
Gemini 3.5 Flash has a documented knowledge cutoff of 2026-01-31, while GPT-5.4's cutoff date is not specified.
We can confirm Gemini 3.5 Flash's training data extends to 2026-01-31, but cannot make a direct comparison without GPT-5.4's cutoff date.
Jan 2026
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Provider Availability
Gemini 3.5 Flash is available from DeepInfra, Google. GPT-5.4 is available from OpenAI.
Gemini 3.5 Flash
GPT-5.4
Outputs Comparison
Judge for yourself.
Run your own prompts against Gemini 3.5 Flash and GPT-5.4 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Gemini 3.5 Flash vs GPT-5.4.