Voxtral Small 24B 2507 vs Step 3.5 Flash vs Grok 4.20

Voxtral Small 24B 2507 at $0.115 in and $0.345 out, Step 3.5 Flash at $0.115 in and $0.345 out, and Grok 4.20 at $1.44 in and $2.88 out — per million tokens, from the same wallet.

Voxtral Small 24B 2507

Mistral AI

0.09¢

for a client proposal

$0.115 in · $0.345 out / 1M

32K context · released October 2025

Full page →

Step 3.5 Flash

StepFun

0.09¢

for a client proposal

$0.115 in · $0.345 out / 1M

262K context · released 6 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 1.1¢ for a typical client proposal.

At a glance

Cheapest input: Voxtral Small 24B 2507 at $0.115 per million tokens.
Cheapest output: Voxtral Small 24B 2507 at $0.345 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

Voxtral Small 24B 2507

0.04¢

Step 3.5 Flash

0.04¢

Grok 4.20

0.43¢

Draft a client proposal from notes

5K in · 800 out

Voxtral Small 24B 2507

0.09¢

Step 3.5 Flash

0.09¢

Grok 4.20

0.95¢

Context-heavy session (Alyph workspace)

155K in · 4K out

Voxtral Small 24B 2507

needs 155K ctx

Step 3.5 Flash

1.9¢

Grok 4.20

$0.23

Analyze a 50-page legal contract

35K in · 1K out

Voxtral Small 24B 2507

needs 35K ctx

Step 3.5 Flash

0.44¢

Grok 4.20

$0.05

Large architecture refactor

250K in · 3K out

Voxtral Small 24B 2507

needs 250K ctx

Step 3.5 Flash

3¢

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

Voxtral Small 24B 2507

Step 3.5 Flash

Grok 4.20

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

Pricing

Voxtral Small 24B 2507

Step 3.5 Flash

Grok 4.20

Input / 1M tokens

$0.115

$1.44

Output / 1M tokens

$0.345

$2.88

Cached input / 1M

$0.011

—

$0.230

Web search

—

0.57¢ / search

Specs

Voxtral Small 24B 2507

Step 3.5 Flash

Grok 4.20

Provider

Mistral AI

StepFun

xAI

Released

October 2025

6 months ago

4 months ago

Context window

32K

262K

Max output

—

66K

—

Input

Text, Audio, and Files

Text

Text, Images, and Files

Output

Text

Reasoning

Answers directly

Shows its thinking

Knowledge cutoff

—

2025-09-01

Try it with real numbers

2K tokens in · 500 tokens out.

Voxtral Small 24B 2507

Mistral AI

0.04¢

for this task

57% input · 43% output

Full pricing →

Step 3.5 Flash

StepFun

0.04¢

for this task

57% input · 43% output

Full pricing →

Grok 4.20

xAI

0.43¢

for this task

67% input · 33% output

Full pricing →

All 3, same prompt and context: 0.51¢. That is the entire cost of the comparison.

Your $5 welcome credit covers about 977 of these.

Which should you pick?

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

On price, Voxtral Small 24B 2507 is the cheapest of the three on a typical task, at about 0.09¢.

For images or files, Voxtral Small 24B 2507 and Grok 4.20 can read them directly; Step 3.5 Flash is text-only.

If you want to watch the model think, Step 3.5 Flash 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 →

Voxtral Small 24B 2507 pricing →Step 3.5 Flash pricing →Grok 4.20 pricing →Try other combinations →

Questions, answered

Which is cheapest — Voxtral Small 24B 2507, Step 3.5 Flash, or Grok 4.20?

On a typical client proposal (5K tokens in, 800 out): Voxtral Small 24B 2507 at 0.09¢; Step 3.5 Flash at 0.09¢; 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 Voxtral Small 24B 2507, Step 3.5 Flash, 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 1.1¢ for a typical task.

Ask all three at once

Identical prompt, identical context, answers side by side — about 1.1¢ for a typical client proposal. Free to start, with $5 of credit.