GPT-5 Pro vs o3 Pro

GPT-5 Pro at $17.25 in and $138.00 out and o3 Pro at $23.00 in and $92.00 out — per million tokens, from the same wallet.

GPT-5 Pro

OpenAI

$0.20

for a client proposal

$17.25 in · $138.00 out / 1M

400K context · released October 2025

Full page →

o3 Pro

OpenAI

$0.19

for a client proposal

$23.00 in · $92.00 out / 1M

200K context · released June 2025

Full page →

Asking all both at once — identical prompt, identical context — costs about $0.39 for a typical client proposal.

At a glance

Cheapest input: GPT-5 Pro at $17.25 per million tokens.
Cheapest output: o3 Pro at $92.00 per million tokens.
Largest context: GPT-5 Pro at 400K tokens — about 570 pages.

Cost per task

Estimated totals at the rates above. Solid bar is input, lighter bar is output.

Quick code fix

2K in · 500 out

GPT-5 Pro

$0.10

o3 Pro

$0.09

Draft a client proposal from notes

5K in · 800 out

GPT-5 Pro

$0.20

o3 Pro

$0.19

Context-heavy session (Alyph workspace)

155K in · 4K out

GPT-5 Pro

$3.23

o3 Pro

$3.93

Analyze a 50-page legal contract

35K in · 1K out

GPT-5 Pro

$0.74

o3 Pro

$0.90

Large architecture refactor

250K in · 3K out

GPT-5 Pro

$4.73

o3 Pro

needs 250K ctx

Solid part of each bar is input tokens, the lighter part is output. Models that don’t fit a task are marked instead of priced.

Cost vs Token Amount

Drag the slider to adjust the split between input and output workload.

80% Input20% Output

GPT-5 Pro

o3 Pro

Adjust the ratio slider to change how output tokens influence the final price for equivalent workloads.

Pricing

GPT-5 Pro

o3 Pro

Input / 1M tokens

$17.25

$23.00

Output / 1M tokens

$138.00

$92.00

Web search

1.1¢ / search

Specs

GPT-5 Pro

o3 Pro

Provider

OpenAI

Released

October 2025

June 2025

Context window

400K

200K

Max output

128K

100K

Input

Images, Text, and Files

Text, Files, and Images

Output

Text

Reasoning

Shows its thinking

Knowledge cutoff

2024-09-30

2024-06-30

Try it with real numbers

2K tokens in · 500 tokens out.

GPT-5 Pro

OpenAI

$0.10

for this task

33% input · 67% output

Full pricing →

o3 Pro

OpenAI

$0.09

for this task

50% input · 50% output

Full pricing →

All 2, same prompt and context: $0.20. That is the entire cost of the comparison.

Your $5 welcome credit covers about 25 of these.

Which should you pick?

For long documents, GPT-5 Pro has the largest context window here — 400K tokens.

On price, o3 Pro is the cheapest of the two on a typical task, at about $0.19.

Or don’t pick. Send the identical prompt to all both, read the answers side by side, and keep the winner. How to run a fair bake-off →

GPT-5 Pro pricing →o3 Pro pricing →Add Lyria 3 Clip Preview Add Grok 4.20

Questions, answered

Which is cheaper, GPT-5 Pro or o3 Pro?

On a typical client proposal (5K tokens in, 800 out): o3 Pro at $0.19; GPT-5 Pro at $0.20. Long prompts can change the order when long-context rates apply.

Which has the largest context window?

GPT-5 Pro — 400K tokens, about 570 pages.

Can I run GPT-5 Pro and o3 Pro side by side on Alyph?

Yes — that is what Alyph is built for: the identical prompt with identical context to all 2, answers rendered side by side, billed from one wallet. This exact combination costs about $0.39 for a typical task.

Ask both at once

Identical prompt, identical context, answers side by side — about $0.39 for a typical client proposal. Free to start, with $5 of credit.