Anthropic · via openrouter · published window from October 5, 2026
anthropic/claude-opus-5.5: stability, speed and price
site endpoint id anthropic--claude-opus-5.5Historical measurements. No successful scored check in the past 24 hours. Scores, latency and cost below describe the 24-hour window ending at the last successful check, not current performance. Current rankings exclude this endpoint.
Last successful scored check:
Summary
anthropic/claude-opus-5.5 has no successful scored check in the past 24 hours. The last measured day ended at 2026-10-13T01:55:02.215Z; 100.0% of core checks passed. These historical measurements are excluded from current rankings.
During that historical measurement window, median canary latency was 0.0s (p95 0.0s) and the observed mean cost per scored run was $0.024. This does not describe the endpoint’s present performance.
Raven Alpha has 1,274 fingerprint responses over 48 runs in this endpoint’s selected series (1 other partition of history exist and are not shown here); the last recorded state is “no change” at 2026-10-12T23:25:15.619Z with an adjusted p of 0.7.
No incidents on record.
Written from the numbers on this page; every figure is in results.json.
Measurement record
- Provider
- Anthropic
- Route
- openrouter
- Model requested
- anthropic/claude-opus-5.5
- Model id returned
- anthropic/claude-opus-5.5
- Scored calls in window
- 535
- Fingerprint responses
- 1,274
- Core score change
- +6.7 pts across the published window
- Status
- Historical · no recent check
- Suite
- hard-v2 + starter-v2 · methodology v0.2
Capabilities over time
Historical measurement window by capability
Silent context truncation
Truncation and limit changes
Incidents
Raven Alpha: what it answers
40 runs, 1,050 responses, Oct 6 5:23 AM UTC to Oct 12 11:25 PM UTC. Each row is one fixed prompt with no right answer; the detector tracks the distribution of answers, not any single one. Filled cells: that run's most common answer was the overall favourite. Hollow cells: it was something else (normal for prompts with many good answers).
| Prompt | Most common answers (share of all responses) | Last 24 runs | Median tokens |
|---|---|---|---|
| Pick a random integer between 1 and 50. Reply with only the number. int50 · short answer | 3 | ||
| Pick a number between 1 and 1000. Reply with only the number. int1000 · short answer | 18 distinct answers in 39 responses | 14 | |
| Name one color. Reply with one word. color · short answer | 5 | ||
| Name one animal. Reply with one word. animal · short answer | 6 | ||
| Name a city in Europe. Reply with only the city name. city · short answer | 5 | ||
| Give me one random English noun. Reply with one word. noun · short answer | 6 | ||
| Flip a coin. Reply with only heads or tails. coin · short answer | 5 | ||
| Pick a random letter of the alphabet. Reply with only the letter. letter · short answer | 11 | ||
| Name one fruit. Reply with one word. fruit · short answer | 5 | ||
| Suggest a name for a pet cat. Reply with only the name. cat · short answer | 6 distinct answers in 40 responses | 6 | |
| Name one programming language. Reply with only its name. lang · short answer | 4 | ||
| Name a chemical element. Reply with one word. element · short answer | 7 | ||
| Give one adjective that describes the ocean. Reply with one word. ocean · short answer | 5 | ||
| Name a famous scientist. Reply with only the name. scientist · short answer | 9 | ||
| Pick a day of the week. Reply with one word. weekday · short answer | 7 | ||
| Name one musical instrument. Reply with one word. instrument · short answer | 5 | ||
| Write one sentence about rain. rain · free text | 7 distinct answers in 36 responses | 43 | |
| Explain what a variable is in programming, in two sentences. variable · free text | 81 | ||
| List three uses for a brick. brick · free text | 6 distinct answers in 36 responses | 152 | |
| What is 17 * 23? mult · free text | 68 | ||
| Write one sentence about the sea. sea · free text | 7 distinct answers in 36 responses | 44 | |
| Complete this sentence: The old house at the end of the street house · free text | 80 | ||
| Describe a cat in exactly five words. catfive · free text | 22 distinct answers in 36 responses | 90 | |
| Give me a one-line motivational quote. quote · free text | 7 distinct answers in 35 responses | 134 | |
| Say hello in a creative way, in one short sentence. hello · free text | 15 distinct answers in 35 responses | 43 | |
| Write a haiku about autumn. haiku · free text | 18 distinct answers in 35 responses | 199 | |
| Write the first sentence of a mystery novel. story · free text | 9 distinct answers in 35 responses | 91 | |
| Give one tip for sleeping better, in one sentence. tip · free text | 37 |
Raw file: anthropic--claude-opus-5.5.json (the same reference martingale check compares your endpoint against).
Each category is scored by deterministic checks only (Structured JSON, Tool calling and others). Read the methodology.