Gemini 3.1 Flash Lite vs KAT-Coder-Pro V2 vs Grok 4.20

Gemini 3.1 Flash Lite at $0.287 in and $1.73 out, KAT-Coder-Pro V2 at $0.345 in and $1.38 out, and Grok 4.20 at $1.44 in and $2.88 out — per million tokens, from the same wallet.

Gemini 3.1 Flash Lite

Google

0.28¢

for a client proposal

$0.287 in · $1.73 out / 1M

1.05M context · released 3 months ago

Full page →

KAT-Coder-Pro V2

Kwaipilot

0.28¢

for a client proposal

$0.345 in · $1.38 out / 1M

256K context · released 4 months ago

Full page →

Grok 4.20

xAI

0.95¢

for a client proposal

$1.44 in · $2.88 out / 1M

2M context · released 4 months ago

Full page →

Asking all three at once — identical prompt, identical context — costs about 1.5¢ for a typical client proposal.

At a glance

Cheapest input: Gemini 3.1 Flash Lite at $0.287 per million tokens.
Cheapest output: KAT-Coder-Pro V2 at $1.38 per million tokens.
Largest context: Grok 4.20 at 2M tokens — about 2,900 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

Gemini 3.1 Flash Lite

0.14¢

KAT-Coder-Pro V2

0.14¢

Grok 4.20

0.43¢

Draft a client proposal from notes

5K in · 800 out

Gemini 3.1 Flash Lite

0.28¢

KAT-Coder-Pro V2

0.28¢

Grok 4.20

0.95¢

Context-heavy session (Alyph workspace)

155K in · 4K out

Gemini 3.1 Flash Lite

$0.05

KAT-Coder-Pro V2

$0.06

Grok 4.20

$0.23

Analyze a 50-page legal contract

35K in · 1K out

Gemini 3.1 Flash Lite

1.2¢

KAT-Coder-Pro V2

1.3¢

Grok 4.20

$0.05

Large architecture refactor

250K in · 3K out

Gemini 3.1 Flash Lite

$0.08

KAT-Coder-Pro V2

$0.09

Grok 4.20

$0.74

Long-context rate applied at this input size.

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

Gemini 3.1 Flash Lite

KAT-Coder-Pro V2

Grok 4.20

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

Pricing

Gemini 3.1 Flash Lite

KAT-Coder-Pro V2

Grok 4.20

Input / 1M tokens

$0.287

$0.345

$1.44

Output / 1M tokens

$1.73

$1.38

$2.88

Cached input / 1M

$0.029

$0.069

$0.230

Web search

1.6¢ / search

—

0.57¢ / search

Specs

Gemini 3.1 Flash Lite

KAT-Coder-Pro V2

Grok 4.20

Provider

Google

Kwaipilot

xAI

Released

3 months ago

4 months ago

Context window

1.05M

256K

Max output

66K

80K

—

Input

Text, Images, Video, Files, and Audio

Text

Text, Images, and Files

Output

Text

Reasoning

Shows its thinking

Answers directly

Shows its thinking

Knowledge cutoff

—

2025-09-01

Try it with real numbers

2K tokens in · 500 tokens out.

Gemini 3.1 Flash Lite

Google

0.14¢

for this task

40% input · 60% output

Full pricing →

KAT-Coder-Pro V2

Kwaipilot

0.14¢

for this task

50% input · 50% output

Full pricing →

Grok 4.20

xAI

0.43¢

for this task

67% input · 33% output

Full pricing →

All 3, same prompt and context: 0.71¢. That is the entire cost of the comparison.

Your $5 welcome credit covers about 701 of these.

Which should you pick?

For long documents, Grok 4.20 has the largest context window here — 2M tokens.

On price, Gemini 3.1 Flash Lite is the cheapest of the three on a typical task, at about 0.28¢.

For images or files, Gemini 3.1 Flash Lite and Grok 4.20 can read them directly; KAT-Coder-Pro V2 is text-only.

If you want to watch the model think, Gemini 3.1 Flash Lite and Grok 4.20 show reasoning; the other answers directly.

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

Gemini 3.1 Flash Lite pricing →KAT-Coder-Pro V2 pricing →Grok 4.20 pricing →Try other combinations →

Questions, answered

Which is cheapest — Gemini 3.1 Flash Lite, KAT-Coder-Pro V2, or Grok 4.20?

On a typical client proposal (5K tokens in, 800 out): Gemini 3.1 Flash Lite at 0.28¢; KAT-Coder-Pro V2 at 0.28¢; Grok 4.20 at 0.95¢. Long prompts can change the order when long-context rates apply.

Which has the largest context window?

Grok 4.20 — 2M tokens, about 2,900 pages.

Can I run Gemini 3.1 Flash Lite, KAT-Coder-Pro V2, and Grok 4.20 side by side on Alyph?

Yes — that is what Alyph is built for: the identical prompt with identical context to all 3, answers rendered side by side, billed from one wallet. This exact combination costs about 1.5¢ for a typical task.

Ask all three at once

Identical prompt, identical context, answers side by side — about 1.5¢ for a typical client proposal. Free to start, with $5 of credit.