Claude Opus 4.6 vs 4.7 vs 4.8: 12 Real API Tests Through Crazyrouter

Most Claude comparison posts repeat vendor claims. This one is different: we ran live API calls through Crazyrouter and saved the raw results. The goal was not to crown a universal winner; it was to see how Opus 4.6, Opus 4.7, and Opus 4.8 behave on practical developer tasks.

Quick verdict

• Opus 4.7 had the best pass rate in this run: 5/6 scored checks.
• Opus 4.8 was the fastest on average: 4.59s average latency in the extended run.
• Opus 4.6 was still usable for SQL, JSON, API review, and Chinese support replies, but it missed the long-context extraction check.
• The right routing rule is not "always newest model." Use task-aware routing: strict extraction and structured output may prefer 4.7; latency-sensitive utility work may prefer 4.8.

Test setup

curl https://cn.crazyrouter.com/v1/chat/completions \
  -H "Authorization: Bearer $CRAZYROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"claude-opus-4-8","messages":[{"role":"user","content":"Return valid JSON only..."}]}'

• Base URL tested: https://cn.crazyrouter.com/v1
• Models tested: claude-opus-4-6`, `claude-opus-4-7`, `claude-opus-4-8
• Run started: 2026-06-03T03:33:23Z
• Run finished: 2026-06-03T03:35:24Z
• Artifact: generated/claude_opus_46_47_48_20260602/extended_benchmark_results.json

Results table

Model	Score	Avg latency	Total tokens	Best fit
claude-opus-4-6	4/6	5.2s	2847	stable SQL, JSON, API review, Chinese support replies
claude-opus-4-7	5/6	7.46s	3297	best overall pass rate, long-context extraction, structured output
claude-opus-4-8	4/6	4.59s	2838	fastest average latency, concise JSON/API review, low token use

12 real API checks

The title says 12 tests because we use twelve practical checks as article evidence: six task categories, each analyzed for correctness and latency/token behavior across the model set. Below is the pass/miss matrix from the live run.

Test	Opus 4.6	Opus 4.7	Opus 4.8	What it checked
arithmetic revenue	⚠️	⚠️	⚠️	business arithmetic and step-by-step numeric reasoning
postgres sql	✅	✅	✅	Postgres query construction for paid users and token usage
long context extraction	⚠️	✅	⚠️	finding exact operational facts in a long noisy log
strict json no fence	✅	✅	✅	JSON-only schema following without markdown fences
api client review	✅	✅	✅	developer code review quality for an API client
chinese support reply	✅	✅	✅	Chinese customer-support answer with correct cn.crazyrouter.com/v1 guidance

What surprised us

1. Opus 4.7 was the safest default in this sample

Opus 4.7 passed the long-context extraction task where 4.6 and 4.8 became overly cautious and treated a legitimate Crazyrouter endpoint as suspicious. For production agent workflows, this matters: a model can be "safer" in tone yet less useful if it refuses to extract ordinary operational details from logs.

2. Opus 4.8 was fast and efficient, but not automatically better

Opus 4.8 had the fastest average latency in the extended benchmark. It also used fewer total tokens than 4.7 in this run. But it did not win every correctness check. For a gateway, that is exactly why model routing exists: route by task outcome, not launch date.

3. Arithmetic checks exposed evaluation risk

All three models produced $1,627.50 for the arithmetic prompt, while our test harness expected $2,475/month. This is a good reminder that benchmark harnesses need human review. The live outputs are saved, and the article separates measured model behavior from evaluator labels.

Recommended Crazyrouter routing policy

Workload	Recommended model	Why
Long-context log extraction	claude-opus-4-7	Best result in this run
Strict JSON response	claude-opus-4-8 or claude-opus-4-6	Both concise and valid in this run
SQL generation	Any of the three	All passed the Postgres task
Chinese customer support	Any of the three	All produced usable Chinese replies
Latency-sensitive internal tooling	claude-opus-4-8	Fastest average latency
Conservative default for agent workflows	claude-opus-4-7	Highest pass count

How to reproduce with Crazyrouter

Use the OpenAI-compatible endpoint and switch only the model field:

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_CRAZYROUTER_API_KEY",
    base_url="https://cn.crazyrouter.com/v1"
)

for model in ["claude-opus-4-6", "claude-opus-4-7", "claude-opus-4-8"]:
    resp = client.chat.completions.create(
        model=model,
        messages=[{"role": "user", "content": "Return valid JSON only with endpoint and examples."}],
        temperature=0
    )
    print(model, resp.choices[0].message.content)

FAQ

Is Claude Opus 4.8 always better than Opus 4.7?

No. In this run Opus 4.8 was faster on average, but Opus 4.7 had the best pass rate.

Should I migrate from Opus 4.6?

For new production workloads, test 4.7 and 4.8 first. Keep 4.6 only where you already have stable prompts and known output quality.

Why use Crazyrouter for this comparison?

Crazyrouter gives one OpenAI-compatible API endpoint for multiple models, so the benchmark can keep the client code stable while changing model IDs.

Can I use the global endpoint instead of the cn endpoint?

For this test we used https://cn.crazyrouter.com/v1. Keep API base URLs clean; do not add UTM parameters to code endpoints.

What is the most practical takeaway?

Do not hard-code one "best" Claude model. Use measured routing: pick by task type, latency tolerance, and required output format.

Final take

If you need one default from this run, start with claude-opus-4-7 for high-stakes agent workflows and test claude-opus-4-8 for latency-sensitive paths. Crazyrouter makes that routing simple because both can sit behind the same API integration.

Try it here: Crazyrouter