Which is more cost-effective, GPT-4o or o3-mini?

Based on 1M input + 1M output tokens, GPT-4o costs $12.50/month versus o3-mini at $5.50/month. The cheaper option depends on your token volume and prompt-to-completion ratio. Use the interactive calculator on this page to enter your exact usage.

How accurate is this cost comparison?

List prices come from each provider's own pricing page and every model page shows when they were last verified. The capability scores are iOPTERA's editorial composites — informed by public benchmarks, not benchmark results themselves; the methodology page explains how they are set.

Which model scores higher on benchmarks?

GPT-4o scores 87 in coding and 90 in reasoning benchmarks. o3-mini scores 88 in coding and 93 in reasoning. See the full 5-category breakdown in the Benchmark Comparison section above.

What are the context window sizes of GPT-4o and o3-mini?

GPT-4o supports a 128K-token context window while o3-mini supports 200K tokens. A larger context window lets you process more text in a single API call.

Which model is faster for real-time applications?

GPT-4o has a speed score of 90/100 and o3-mini scores 78/100 on our latency benchmark. For interactive chatbots and low-latency tasks, the higher speed score is preferable.

Can I calculate costs for my specific token volume?

Yes. Use the interactive cost calculator on this page. Enter your monthly token volume and adjust the prompt-to-completion ratio. You can also use presets for common scenarios like Customer Support Bots (~30M tokens/month) or Document Summarizers (~15M tokens/month).

Cost and performance comparison

GPT-4o vs o3-mini

Model AOpenAI

GPT-4o

Capability score (editorial)90/100

Cost / 1M Tokens: $4.75; 70% in · 30% out mix
Value Index (score÷cost): 18.9; Higher = better value

Speed: 90/100
Context: 128K
Tier: Smart Tier

List price from the OpenAI pricing page, verified September 30, 2026.

Check the source

How we verify prices

Model BOpenAI

o3-mini

Capability score (editorial)93/100

Cost / 1M Tokens: $2.09; 70% in · 30% out mix
Value Index (score÷cost): 44.5; Higher = better value

Speed: 78/100
Context: 200K
Tier: Smart Tier

List price from the OpenAI pricing page, verified September 30, 2026.

Check the source

How we verify prices

In-depth analysis

GPT-4o vs o3-mini: Detailed Comparison

GPT-4o is OpenAI's mid-range-tier language model with a 128K-token context window, excelling at vision/multimodal. o3-mini from OpenAI is a mid-range-tier model supporting 200K tokens in context, with standout performance in reasoning.

o3-mini is both the cheaper and the stronger model here — for the same text it costs 56% less than GPT-4o and still leads on combined coding and reasoning by 4 points. There is no tradeoff to weigh on this pair: unless you need something specific from GPT-4o, the cheaper model is simply the better one. GPT-4o is priced at $2.50/M input tokens and $10.00/M output tokens. o3-mini costs $1.10/M input and $4.40/M output.

On iOPTERA's editorial scores, o3-mini leads with 88/100 for coding and 93/100 for reasoning, against GPT-4o's 87/100 and 90/100.

Capability breakdown

Across the five core benchmark categories, here is how GPT-4o and o3-mini stack up head to head:

coding

o3-mini leads

reasoning

o3-mini leads

data extraction

GPT-4o leads

creative tasks

GPT-4o leads

vision/multimodal

GPT-4o leads

Best model by task

coding: o3-mini wins with 88/100
reasoning: o3-mini wins with 93/100
data extraction: GPT-4o wins with 92/100
creative tasks: GPT-4o wins with 92/100
vision/multimodal: GPT-4o wins with 95/100

Estimated monthly cost at scale

For 10M + 2M tokens of text a month (counted the way OpenAI's tokenizer counts), GPT-4o runs about $45.00 while o3-mini runs about $19.80 — o3-mini saves roughly $25.20 (56%) every month.

What actually decides it

Both models come from OpenAI, so they share a tokenizer, an API surface, and a billing account. Switching between them is a model-string change and nothing else — no new SDK, no re-tokenizing your prompts to re-estimate cost, no second vendor to onboard. That makes routing between them far cheaper to implement than a cross-vendor split.

These are the same lab's model at the same tier, 8 months apart — so this is an upgrade question, not a choice between alternatives. o3-mini is the current entry; GPT-4o is here because plenty of production traffic still runs on it. If you are starting something new there is little reason to pick the older one, and if you are already on it the question is whether the migration cost is worth the gain.

o3-mini carries the larger context window at 200K tokens versus 128K for GPT-4o. The gap is real but not decisive — it matters if your prompts routinely run long, and is irrelevant if they sit where most production prompts sit, well under 100K. Bear in mind that filling a large window is also what makes a request expensive.

Throughput is close enough to ignore — 90/100 versus 78/100. Neither model will feel noticeably quicker in an interactive product, so latency is not a reason to choose between them.

o3-mini wins this comparison outright — cheaper and stronger. Choose GPT-4o only if it has a specific capability you need; on price and benchmarks it is behind on both.

What you actually pay

The list price is only the start. Prompt caching, batch processing and long prompts change the bill, and each provider sets them differently. Prices per 1M tokens.

Pricing terms beyond the list price, per 1M tokens
Pricing term	GPT-4o	o3-mini
List price (input / output)	$2.50 / $10.00	$1.10 / $4.40
Cached input	$1.2550% of the input price	—
Batch API	50% off input and output	—
Long prompts	—	—
Input with 80% cache hits	$1.50	—

The last row assumes 80% of input tokens are read from the cache, as in a chat app that re-sends a long system prompt or RAG over the same documents. Cache-write and storage charges are not included.

Checked on October 8, 2026 against the pricing pages of OpenAI.

Capability scores

iOPTERA editorial scores across 5 categories — informed by public benchmarks, not measured by us

CategoryGPT-4oo3-miniWinner

Coding

Reasoning

Extraction

Creative

Vision

GPT-4o: 3 wins

o3-mini: 2 wins

GPT-4o leads overall

Speed Score

90/100vs78/100

GPT-4oo3-mini

Context Window

128Kvs200K

GPT-4oo3-mini

What Is a Token?

Models don't read words — they process tokens.

A token is roughly 4 characters of English text (~¾ of a word). Your API bill is priced per million tokens — understanding this directly reduces your costs.

Short phrase

"Hello, world!"

4 tokens

GPT-4o: $1.00
o3-mini: $0.44

Business email

One typical email (~200 words)

~270 tokens

GPT-4o: $67.50
o3-mini: $29.70

Code file

50-line Python script

~400 tokens

GPT-4o: $100.00
o3-mini: $44.00

Prices shown are for 100,000 runs of each workload — one run costs a fraction of a cent on both GPT-4o and o3-mini, so the number only becomes meaningful at production volume. Input tokens only; add your output volume in the calculator below.

How to check your token usage

response.usage.total_tokens

Every API response includes a usage object. Sum total_tokens across all calls to get your monthly figure, then use the calculator below.

Your Cost Calculator

Enter your actual monthly token usage to see real savings

Quick Presets

Monthly Token Volume

30M tokens

Prompt / Completion Split

Prompt 70%Completion 30%

GPT-4o

$142.50/mo

$1,710.00/yr

$2.50/M input$10.00/M output

Cheaper

o3-mini

$62.70/mo

$752.40/yr

$1.10/M input$4.40/M output

Annual Savings

$957.60 saved per year

o3-mini cheaper · $79.80/mo

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