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RDT-1B vs OpenVLA-7B: 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
VLA / Robotics
vs
xAI
VLA / Robotics
Verdict

RDT-1B and OpenVLA-7B 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

SpecRDT-1BOpenVLA-7B
ProviderxAIxAI
CategoryVLA / RoboticsVLA / Robotics
Input cost / 1M tokensFreeFree
Output cost / 1M tokensFreeFree
Context window——
Max output tokens——
Avg. latency——
Featured——
New——
Capabilities
image
text
image
text

Pricing example

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

RDT-1B
€0.0000

100K in × Free + 50K out × Free

OpenVLA-7B
€0.0000

100K in × Free + 50K out × Free

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 RDT-1B
let r = await client.chat.completions.create({
  model: "robotics-diffusion-transformer/rdt-1b",
  messages: [{ role: "user", content: "Hello" }],
});

// After — switched to OpenVLA-7B
r = await client.chat.completions.create({
  model: "openvla/openvla-7b",
  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 RDT-1B
r = client.chat.completions.create(
    model="robotics-diffusion-transformer/rdt-1b",
    messages=[{"role": "user", "content": "Hello"}],
)

# After — switched to OpenVLA-7B
r = client.chat.completions.create(
    model="openvla/openvla-7b",
    messages=[{"role": "user", "content": "Hello"}],
)
cURL
# Before — using RDT-1B
curl https://railwail.com/v1/chat/completions \
  -H "Authorization: Bearer $RAILWAIL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "robotics-diffusion-transformer/rdt-1b",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

# After — switched to OpenVLA-7B
curl https://railwail.com/v1/chat/completions \
  -H "Authorization: Bearer $RAILWAIL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openvla/openvla-7b",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

Which one wins for...

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

Coding
RDT-1B

Higher coding category match or larger context wins.

Writing
RDT-1B

Bigger context window helps maintain long-form coherence.

Long documents
RDT-1B

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
Tie

The model with the lower input-token price wins.

Frequently asked questions

Which is cheaper, RDT-1B or OpenVLA-7B?
Pricing for RDT-1B and OpenVLA-7B is comparable on input tokens. For a 100K input + 50K output workload, RDT-1B costs about €0.0000 and OpenVLA-7B costs about €0.0000.
Which has more context, RDT-1B or OpenVLA-7B?
RDT-1B and OpenVLA-7B have similar context windows (— vs —).
Is RDT-1B better than OpenVLA-7B for coding?
For coding-heavy workloads we lean toward RDT-1B 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 RDT-1B and OpenVLA-7B via Railwail?
Yes. Both RDT-1B and OpenVLA-7B 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 RDT-1B to OpenVLA-7B?
Replace the model identifier "robotics-diffusion-transformer/rdt-1b" with "openvla/openvla-7b" 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 RDT-1B and OpenVLA-7B side by side

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

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