Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
Workload (per month)
Google: Gemini 4 Argon
OpenAI: GPT-5.4
Difference
Customer-support chatbot
50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens)
$350
$488
Google: Gemini 4 Argon saves $138
RAG search over documents
20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens)
$340
$450
Google: Gemini 4 Argon saves $110
Coding / tool-using agent
2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens)
$360
$480
Google: Gemini 4 Argon saves $120
Batch summarisation
10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens)
$220
$290
Google: Gemini 4 Argon saves $70.00
Long-document analysis
500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens)
$110
$140
Google: Gemini 4 Argon saves $30.00
Capabilities side by side
Capability
Google: Gemini 4 Argon
OpenAI: GPT-5.4
What it lets you do
Tool / function calling
✓ Yes
✓ Yes
call your APIs and run agent loops
Structured output (JSON schema)
✓ Yes
✓ Yes
return JSON that validates against your schema
Reasoning / thinking mode
✓ Yes
✓ Yes
spend extra tokens thinking before answering hard problems
Image input
✓ Yes
✓ Yes
read screenshots, charts and scanned pages
Audio input
✓ Yes
—
take speech or audio directly
File / PDF input
✓ Yes
✓ Yes
accept documents without your own parsing step
Image output
—
—
generate images, not just text
Built-in web search
✓ Yes
✓ Yes
answer from live web results
Seed (reproducible sampling)
✓ Yes
✓ Yes
repeat a generation for tests and evals
Log-probabilities
—
—
read token confidence for classification and scoring
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
Google: Gemini 4 Argon: price unchanged since we started tracking it on 2026-10-14.
OpenAI: GPT-5.4: price unchanged since we started tracking it on 2026-03-10.
Which should you choose?
Choose Google: Gemini 4 Argon if…
cost matters at scale — it is 29% cheaper on a typical 3:1 input/output mix ($350 vs $488 a month for 50,000 support chats)
you need audio input — to take speech or audio directly; OpenAI: GPT-5.4 does not advertise it
you want the newer model — released 2026-10-13, 7 months after the other
Choose OpenAI: GPT-5.4 if…
you generate long outputs in one go — up to 128K tokens (about 96,000 words) per response
Frequently asked questions
Is Google: Gemini 4 Argon better than OpenAI: GPT-5.4?
Neither wins outright: Google: Gemini 4 Argon is the pick when cost matters at scale, OpenAI: GPT-5.4 when you generate long outputs in one go. In short: Google: Gemini 4 Argon when cost matters at scale, you need audio input, you want the newer model; OpenAI: GPT-5.4 when you generate long outputs in one go.
Which is cheaper, Google: Gemini 4 Argon or OpenAI: GPT-5.4?
Google: Gemini 4 Argon is cheaper: $4.00 vs $5.63 per 1M tokens at a typical 3:1 input/output mix, 29% less. For 50,000 support conversations a month that is $350 against $488.
How much do Google: Gemini 4 Argon and OpenAI: GPT-5.4 cost per million tokens?
Google: Gemini 4 Argon costs $2.00 per 1M input tokens and $10.00 per 1M output tokens; OpenAI: GPT-5.4 costs $2.50 input and $15.00 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, Google: Gemini 4 Argon or OpenAI: GPT-5.4?
OpenAI: GPT-5.4: 1.1M tokens, about 1,575 pages, against 1.0M (about 1,573 pages) for Google: Gemini 4 Argon.
Do Google: Gemini 4 Argon and OpenAI: GPT-5.4 support function calling and JSON output?
Gemini 4 Argon is Google's flagship reasoning model, built for complex software engineering, deep mathematical and scientific problem solving, and autonomous multi-step agents. Google trained it to keep context across...
GPT-5.4 is OpenAI’s latest frontier model, unifying the Codex and GPT lines into a single system. It features a 1M+ token context window (922K input, 128K output) with support for...