Claude Haiku 4.5 vs Claude Sonnet 4.6: 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.
Choose Claude Haiku 4.5 for cost-sensitive workloads — it is roughly 3.0× cheaper on input tokens. Choose Claude Sonnet 4.6 when you need its broader capabilities or stronger benchmarks.
Choose Claude Sonnet 4.6 for long documents (1.0M tokens context). Choose Claude Haiku 4.5 for shorter prompts where the smaller window keeps latency and cost down.
Side-by-side specs
| Spec | Claude Haiku 4.5 | Claude Sonnet 4.6 |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Category | Multimodal | Multimodal |
| Input cost / 1M tokens | $1.20 | $3.60 |
| Output cost / 1M tokens | $6.00 | $18.00 |
| Context window | 200K tokens | 1.0M tokens |
| Max output tokens | 64,000 | 128,000 |
| Avg. latency | — | — |
| Featured | — | Yes |
| New | Yes | Yes |
| Capabilities | text image | text image |
Pricing example
A typical chat workload of 100,000 input tokens plus 50,000 output tokens.
100K in × $1.20 + 50K out × $6.00
100K in × $3.60 + 50K out × $18.00
For this workload, Claude Haiku 4.5 is cheaper than Claude Sonnet 4.6 by $0.84 per request.
Switch in one line
Both models live behind Railwail's OpenAI-compatible endpoint. Replace the model string and you are done.
import OpenAI from "openai";
const client = new OpenAI({
apiKey: process.env.RAILWAIL_API_KEY,
baseURL: "https://railwail.com/v1",
});
// Before — using Claude Haiku 4.5
let r = await client.chat.completions.create({
model: "claude-haiku-4-5-20251001",
messages: [{ role: "user", content: "Hello" }],
});
// After — switched to Claude Sonnet 4.6
r = await client.chat.completions.create({
model: "claude-sonnet-4-6",
messages: [{ role: "user", content: "Hello" }],
});from openai import OpenAI
client = OpenAI(
api_key=os.environ["RAILWAIL_API_KEY"],
base_url="https://railwail.com/v1",
)
# Before — using Claude Haiku 4.5
r = client.chat.completions.create(
model="claude-haiku-4-5-20251001",
messages=[{"role": "user", "content": "Hello"}],
)
# After — switched to Claude Sonnet 4.6
r = client.chat.completions.create(
model="claude-sonnet-4-6",
messages=[{"role": "user", "content": "Hello"}],
)# Before — using Claude Haiku 4.5
curl https://railwail.com/v1/chat/completions \
-H "Authorization: Bearer $RAILWAIL_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "claude-haiku-4-5-20251001",
"messages": [{"role": "user", "content": "Hello"}]
}'
# After — switched to Claude Sonnet 4.6
curl https://railwail.com/v1/chat/completions \
-H "Authorization: Bearer $RAILWAIL_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "claude-sonnet-4-6",
"messages": [{"role": "user", "content": "Hello"}]
}'Which one wins for...
Quick verdicts derived from public specs. Always validate on your own workload.
Higher coding category match or larger context wins.
Bigger context window helps maintain long-form coherence.
The larger context window is the deciding factor.
Multimodal/vision support is required for image inputs.
Lower average latency wins for interactive UX.
The model with the lower input-token price wins.
Frequently asked questions
Try Claude Haiku 4.5 and Claude Sonnet 4.6 side by side
One API key, one endpoint, both models. Start free — no credit card required.