Claude Opus 4.8 (Fast) vs GPT-4 Turbo

Claude Opus 4.8 (Fast) at $11.50 in and $57.50 out and GPT-4 Turbo at $11.50 in and $34.50 out — per million tokens, from the same wallet.

Claude Opus 4.8 (Fast)

Anthropic

$0.10

for a client proposal

$11.50 in · $57.50 out / 1M

1M context · released 2 months ago

Full page →

GPT-4 Turbo

OpenAI

$0.09

for a client proposal

$11.50 in · $34.50 out / 1M

128K context · released April 2024

Full page →

Asking all both at once — identical prompt, identical context — costs about $0.19 for a typical client proposal.

At a glance

All 2 cost the same on input.
Cheapest output: GPT-4 Turbo at $34.50 per million tokens.
Largest context: Claude Opus 4.8 (Fast) at 1M tokens — about 1,400 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

Claude Opus 4.8 (Fast)

$0.05

GPT-4 Turbo

4¢

Draft a client proposal from notes

5K in · 800 out

Claude Opus 4.8 (Fast)

$0.10

GPT-4 Turbo

$0.09

Context-heavy session (Alyph workspace)

155K in · 4K out

Claude Opus 4.8 (Fast)

$2.01

GPT-4 Turbo

needs 155K ctx

Analyze a 50-page legal contract

35K in · 1K out

Claude Opus 4.8 (Fast)

$0.46

GPT-4 Turbo

$0.44

Large architecture refactor

250K in · 3K out

Claude Opus 4.8 (Fast)

$3.05

GPT-4 Turbo

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

Claude Opus 4.8 (Fast)

GPT-4 Turbo

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

Pricing

Claude Opus 4.8 (Fast)

GPT-4 Turbo

Input / 1M tokens

$11.50

Output / 1M tokens

$57.50

$34.50

Cached input / 1M

$1.15

—

Web search

1.1¢ / search

—

Specs

Claude Opus 4.8 (Fast)

GPT-4 Turbo

Provider

Anthropic

OpenAI

Released

2 months ago

April 2024

Context window

128K

Max output

128K

Input

Text, Images, and Files

Text and Images

Output

Text

Reasoning

Shows its thinking

Answers directly

Knowledge cutoff

—

2023-12-31

Try it with real numbers

2K tokens in · 500 tokens out.

Claude Opus 4.8 (Fast)

Anthropic

$0.05

for this task

44% input · 56% output

Full pricing →

GPT-4 Turbo

OpenAI

4¢

for this task

57% input · 43% output

Full pricing →

All 2, same prompt and context: $0.09. That is the entire cost of the comparison.

Your $5 welcome credit covers about 54 of these.

Which should you pick?

For long documents, Claude Opus 4.8 (Fast) has the largest context window here — 1M tokens.

On price, GPT-4 Turbo is the cheapest of the two on a typical task, at about $0.09.

If you want to watch the model think, Claude Opus 4.8 (Fast) shows reasoning; the other answers directly.

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 →

Claude Opus 4.8 (Fast) pricing →GPT-4 Turbo pricing →Add Lyria 3 Clip Preview Add Grok 4.20

Questions, answered

Which is cheaper, Claude Opus 4.8 (Fast) or GPT-4 Turbo?

On a typical client proposal (5K tokens in, 800 out): GPT-4 Turbo at $0.09; Claude Opus 4.8 (Fast) at $0.10. Long prompts can change the order when long-context rates apply.

Which has the largest context window?

Claude Opus 4.8 (Fast) — 1M tokens, about 1,400 pages.

Can I run Claude Opus 4.8 (Fast) and GPT-4 Turbo 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 $0.19 for a typical task.

Ask both at once

Identical prompt, identical context, answers side by side — about $0.19 for a typical client proposal. Free to start, with $5 of credit.