Grok 4.3 vs GPT-5.4 Mini: Which AI Model Should You Choose?

Pricing, context windows, latency, capabilities, and a one-line code switch — everything you need to pick the right model.

xAI
Multimodal
vs
OpenAI
Multimodal
Verdict

Grok 4.3 and GPT-5.4 Mini are closely matched on pricing and context. The right choice depends on your specific workload — see the table below for the full breakdown.

Side-by-side specs

SpecGrok 4.3GPT-5.4 Mini
ProviderxAIOpenAI
CategoryMultimodalMultimodal
Input cost / 1M tokens€0.0010€0.0010
Output cost / 1M tokens€0.0030€0.0050
Context window1.0M tokens400K tokens
Max output tokens1,000,000128,000
Avg. latency
FeaturedYesYes
NewYesYes
Capabilities
text
image
text
image

Pricing example

A typical chat workload of 100,000 input tokens plus 50,000 output tokens.

Grok 4.3
0.0003

100K in × €0.0010 + 50K out × €0.0030

GPT-5.4 Mini
0.0003

100K in × €0.0010 + 50K out × €0.0050

For this workload, Grok 4.3 is cheaper than GPT-5.4 Mini by 0.0001 per request.

Switch in one line

Both models live behind Railwail's OpenAI-compatible endpoint. Replace the model string and you are done.

JavaScript / TypeScript
import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.RAILWAIL_API_KEY,
  baseURL: "https://railwail.com/v1",
});

// Before — using Grok 4.3
let r = await client.chat.completions.create({
  model: "grok-4.3",
  messages: [{ role: "user", content: "Hello" }],
});

// After — switched to GPT-5.4 Mini
r = await client.chat.completions.create({
  model: "gpt-5.4-mini",
  messages: [{ role: "user", content: "Hello" }],
});
Python
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["RAILWAIL_API_KEY"],
    base_url="https://railwail.com/v1",
)

# Before — using Grok 4.3
r = client.chat.completions.create(
    model="grok-4.3",
    messages=[{"role": "user", "content": "Hello"}],
)

# After — switched to GPT-5.4 Mini
r = client.chat.completions.create(
    model="gpt-5.4-mini",
    messages=[{"role": "user", "content": "Hello"}],
)
cURL
# Before — using Grok 4.3
curl https://railwail.com/v1/chat/completions \
  -H "Authorization: Bearer $RAILWAIL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "grok-4.3",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

# After — switched to GPT-5.4 Mini
curl https://railwail.com/v1/chat/completions \
  -H "Authorization: Bearer $RAILWAIL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5.4-mini",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

Which one wins for...

Quick verdicts derived from public specs. Always validate on your own workload.

Coding
Grok 4.3

Higher coding category match or larger context wins.

Writing
Grok 4.3

Bigger context window helps maintain long-form coherence.

Long documents
Grok 4.3

The larger context window is the deciding factor.

Vision
Tie

Multimodal/vision support is required for image inputs.

Real-time chat
Tie

Lower average latency wins for interactive UX.

Cost-sensitive
GPT-5.4 Mini

The model with the lower input-token price wins.

Frequently asked questions

Which is cheaper, Grok 4.3 or GPT-5.4 Mini?
GPT-5.4 Mini is cheaper. On a 100K input + 50K output example, Grok 4.3 costs about €0.0003 versus €0.0003 for GPT-5.4 Mini — a saving of €0.0001.
Which has more context, Grok 4.3 or GPT-5.4 Mini?
Grok 4.3 has the larger context window at 1.0M tokens, compared to 400K tokens for GPT-5.4 Mini.
Is Grok 4.3 better than GPT-5.4 Mini for coding?
For coding-heavy workloads we lean toward Grok 4.3 on this comparison — it scores higher on the relevant heuristics (category, tags, or context window). Both models are usable for code via Railwail's OpenAI-compatible endpoint, so the safest path is to A/B test on your own prompts.
Can I use both Grok 4.3 and GPT-5.4 Mini via Railwail?
Yes. Both Grok 4.3 and GPT-5.4 Mini are accessible through a single Railwail API key and the OpenAI-compatible /v1/chat/completions endpoint. You only change the "model" parameter to switch between them — no SDK swap, no separate billing.
How do I switch from Grok 4.3 to GPT-5.4 Mini?
Replace the model identifier "grok-4.3" with "gpt-5.4-mini" in your request payload. Everything else — API key, base URL, request shape — stays the same. See the code example on this page for the exact one-line change.

Try Grok 4.3 and GPT-5.4 Mini side by side

One API key, one endpoint, both models. Start free — no credit card required.