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Granite Code 8B vs Granite Code 20B: 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.

Replicate
Code
vs
Replicate
Code
Verdict

Choose Granite Code 8B for long documents (128K tokens context). Choose Granite Code 20B for shorter prompts where the smaller window keeps latency and cost down.

Side-by-side specs

SpecGranite Code 8BGranite Code 20B
ProviderReplicateReplicate
CategoryCodeCode
Input cost / 1M tokens$0.060$0.12
Output cost / 1M tokens$0.30$0.60
Context window128K tokens8K tokens
Max output tokens8,1928,192
Avg. latency——
Featured——
New——
Capabilities
text
text

Pricing example

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

Granite Code 8B
$0.021

100K in × $0.060 + 50K out × $0.30

Granite Code 20B
$0.042

100K in × $0.12 + 50K out × $0.60

For this workload, Granite Code 8B is cheaper than Granite Code 20B by $0.021 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 Granite Code 8B
let r = await client.chat.completions.create({
  model: "ibm-granite/granite-8b-code-instruct-128k",
  messages: [{ role: "user", content: "Hello" }],
});

// After — switched to Granite Code 20B
r = await client.chat.completions.create({
  model: "ibm-granite/granite-20b-code-instruct-8k",
  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 Granite Code 8B
r = client.chat.completions.create(
    model="ibm-granite/granite-8b-code-instruct-128k",
    messages=[{"role": "user", "content": "Hello"}],
)

# After — switched to Granite Code 20B
r = client.chat.completions.create(
    model="ibm-granite/granite-20b-code-instruct-8k",
    messages=[{"role": "user", "content": "Hello"}],
)
cURL
# Before — using Granite Code 8B
curl https://railwail.com/v1/chat/completions \
  -H "Authorization: Bearer $RAILWAIL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "ibm-granite/granite-8b-code-instruct-128k",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

# After — switched to Granite Code 20B
curl https://railwail.com/v1/chat/completions \
  -H "Authorization: Bearer $RAILWAIL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "ibm-granite/granite-20b-code-instruct-8k",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

Which one wins for...

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

Coding
Granite Code 8B

Higher coding category match or larger context wins.

Writing
Granite Code 8B

Bigger context window helps maintain long-form coherence.

Long documents
Granite Code 8B

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
Granite Code 8B

The model with the lower input-token price wins.

Frequently asked questions

Which is cheaper, Granite Code 8B or Granite Code 20B?
Granite Code 8B is cheaper. On a 100K input + 50K output example, Granite Code 8B costs about $0.021 versus $0.042 for Granite Code 20B — a saving of $0.021.
Which has more context, Granite Code 8B or Granite Code 20B?
Granite Code 8B has the larger context window at 128K tokens, compared to 8K tokens for Granite Code 20B.
Is Granite Code 8B better than Granite Code 20B for coding?
For coding-heavy workloads we lean toward Granite Code 8B 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 Granite Code 8B and Granite Code 20B via Railwail?
Yes. Both Granite Code 8B and Granite Code 20B 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 Granite Code 8B to Granite Code 20B?
Replace the model identifier "ibm-granite/granite-8b-code-instruct-128k" with "ibm-granite/granite-20b-code-instruct-8k" 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 Granite Code 8B and Granite Code 20B side by side

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

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