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Grok 4.3 vs GPT-5.4: 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

Choose Grok 4.3 for cost-sensitive workloads — it is roughly 3.0× cheaper on input tokens. Choose GPT-5.4 when you need its broader capabilities or stronger benchmarks.

Side-by-side specs

SpecGrok 4.3GPT-5.4
ProviderxAIOpenAI
CategoryMultimodalMultimodal
Input cost / 1M tokens€0.0010€0.0030
Output cost / 1M tokens€0.0030€0.015
Context window1.0M tokens1.1M 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
€0.0011

100K in × €0.0030 + 50K out × €0.015

For this workload, Grok 4.3 is cheaper than GPT-5.4 by €0.0008 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
r = await client.chat.completions.create({
  model: "gpt-5.4",
  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
r = client.chat.completions.create(
    model="gpt-5.4",
    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
curl https://railwail.com/v1/chat/completions \
  -H "Authorization: Bearer $RAILWAIL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5.4",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

Which one wins for...

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

Coding
GPT-5.4

Higher coding category match or larger context wins.

Writing
GPT-5.4

Bigger context window helps maintain long-form coherence.

Long documents
GPT-5.4

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
Grok 4.3

The model with the lower input-token price wins.

Frequently asked questions

Which is cheaper, Grok 4.3 or GPT-5.4?
Grok 4.3 is cheaper. On a 100K input + 50K output example, Grok 4.3 costs about €0.0003 versus €0.0011 for GPT-5.4 — a saving of €0.0008.
Which has more context, Grok 4.3 or GPT-5.4?
GPT-5.4 has the larger context window at 1.1M tokens, compared to 1.0M tokens for Grok 4.3.
Is Grok 4.3 better than GPT-5.4 for coding?
For coding-heavy workloads we lean toward GPT-5.4 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 via Railwail?
Yes. Both Grok 4.3 and GPT-5.4 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?
Replace the model identifier "grok-4.3" with "gpt-5.4" 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 side by side

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

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