Cogito v2.1 671B vs Hermes 4 405B

Cogito v2.1 671B at $1.44 in and $1.44 out and Hermes 4 405B at $1.15 in and $3.45 out — per million tokens, from the same wallet.

Cogito v2.1 671B

Deep Cogito

0.83¢

for a client proposal

$1.44 in · $1.44 out / 1M

128K context · released November 2025

Full page →

Hermes 4 405B

Nous Research

0.85¢

for a client proposal

$1.15 in · $3.45 out / 1M

131K context · released August 2025

Full page →

Asking all both at once — identical prompt, identical context — costs about 1.7¢ for a typical client proposal.

At a glance

Cheapest input: Hermes 4 405B at $1.15 per million tokens.
Cheapest output: Cogito v2.1 671B at $1.44 per million tokens.
Largest context: Hermes 4 405B at 131K tokens — about 190 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

Cogito v2.1 671B

0.36¢

Hermes 4 405B

0.4¢

Draft a client proposal from notes

5K in · 800 out

Cogito v2.1 671B

0.83¢

Hermes 4 405B

0.85¢

Context-heavy session (Alyph workspace)

155K in · 4K out

Cogito v2.1 671B

needs 155K ctx

Hermes 4 405B

needs 155K ctx

Analyze a 50-page legal contract

35K in · 1K out

Cogito v2.1 671B

$0.05

Hermes 4 405B

4.4¢

Large architecture refactor

250K in · 3K out

Cogito v2.1 671B

needs 250K ctx

Hermes 4 405B

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

Cogito v2.1 671B

Hermes 4 405B

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

Pricing

Cogito v2.1 671B

Hermes 4 405B

Input / 1M tokens

$1.44

$1.15

Output / 1M tokens

$1.44

$3.45

Specs

Cogito v2.1 671B

Hermes 4 405B

Provider

Deep Cogito

Nous Research

Released

November 2025

August 2025

Context window

128K

131K

Max output

—

Input

Text

Output

Text

Reasoning

Shows its thinking

Knowledge cutoff

—

2024-08-31

Try it with real numbers

2K tokens in · 500 tokens out.

Cogito v2.1 671B

Deep Cogito

0.36¢

for this task

80% input · 20% output

Full pricing →

Hermes 4 405B

Nous Research

0.4¢

for this task

57% input · 43% output

Full pricing →

All 2, same prompt and context: 0.76¢. That is the entire cost of the comparison.

Your $5 welcome credit covers about 656 of these.

Which should you pick?

For long documents, Hermes 4 405B has the largest context window here — 131K tokens.

On price, Cogito v2.1 671B is the cheapest of the two on a typical task, at about 0.83¢.

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 →

Cogito v2.1 671B pricing →Hermes 4 405B pricing →Add Lyria 3 Clip Preview Add Grok 4.20

Questions, answered

Which is cheaper, Cogito v2.1 671B or Hermes 4 405B?

On a typical client proposal (5K tokens in, 800 out): Cogito v2.1 671B at 0.83¢; Hermes 4 405B at 0.85¢. Long prompts can change the order when long-context rates apply.

Which has the largest context window?

Hermes 4 405B — 131K tokens, about 190 pages.

Can I run Cogito v2.1 671B and Hermes 4 405B 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 1.7¢ for a typical task.

Ask both at once

Identical prompt, identical context, answers side by side — about 1.7¢ for a typical client proposal. Free to start, with $5 of credit.