Claude Opus 5.5 is now listed on AIxploria, the AI tools directory, with a card that went live at 03:23 UTC on 24 September 2026. That is about 35 hours after Anthropic released the model. The card calls it “an AI model built for code and autonomous agents,” gives it a four-and-a-half-star rating and badges it “#4 in LLM models.”
We checked the card line by line against Anthropic’s launch post, model documentation and pricing page. Most of it is accurate. But it contradicts itself on the context window, misstates a launch detail, leaves out the benchmarks where Claude Opus 5.5 loses, and claims a ranking slot that the directory has already given to another model.
This is the latest in our series on new AIxploria listings. For the launch itself and how it compares with OpenAI’s same-day release, see Anthropic and OpenAI Announce More Powerful (and Cheaper) AI Models.
Table of contents
- The Claude Opus 5.5 Card at a Glance
- What Anthropic Actually Launched
- Claude Opus 5.5 Card Claims Checked Against Anthropic
- Two Contradictions Inside the Claude Opus 5.5 Card
- The Benchmarks the Claude Opus 5.5 Card Leaves Out
- What “40% Cheaper” Really Means for Claude Opus 5.5
- Claude Opus 5.5 Against GPT-6 Sol on Price
- The Rank Badge: Claude Opus 5.5 Claims a Slot Grok 4.6 Holds
- Has Claude Opus 5.5 Reached AIxploria’s Ranked Lists Yet?
- What the Claude Opus 5.5 Card Gets Right
- Should You Use Claude Opus 5.5?
- Frequently Asked Questions About Claude Opus 5.5
- References
The Claude Opus 5.5 Card at a Glance
AIxploria is a large directory of AI tools, sorted into categories and ranked lists. Each tool gets a card with a short blurb, a longer review, tags, a rating and a rank badge.
The basics
The card sits at aixploria.com/en/claude-opus-5-5-anthropic/. Its page title promises “Reviews, Price, Info & 48 Alternatives.” It is tagged “Latest AI” and “LLM models,” marked as a Verified Tool and labelled Freemium. It was published at 03:23:59 UTC and last edited six minutes later.
The numbers on the card
The Claude Opus 5.5 card shows 124 upvotes. Its star rating reads 4.57 out of 5, and the page’s structured data shows that figure comes from seven votes. Seven votes, cast within hours of publication, is a measure of early enthusiasm rather than a considered verdict.
The headline claim
The review opens with “Anthropic’s frontier model drops to $4 per million tokens.” The blurb adds that the model has “a context window of one million tokens” and is “40% less expensive than its predecessor (Opus 5).” Those are the claims most readers will take away, so we started there.
How fast the card appeared
Anthropic launched Claude Opus 5.5 on 22 September, about 90 minutes before OpenAI’s 18:00 UTC release of GPT-6 Sol and Luna, according to TechCrunch. The card followed roughly 35 hours later. Earlier cards for major model launches in this series appeared one to three days after release, so this is at the quick end of normal.
What Anthropic Actually Launched
Before judging the card, it helps to set out what Anthropic says about Claude Opus 5.5 in its own words.
The pitch
Claude Opus 5.5 is “the first model in our new Claude 5.5 family,” Anthropic says. “It performs at the level of Claude Fable 5.1 on most work and costs 40% less to run than Opus 5.” Sonnet 5.5 and Haiku 5.5 “will follow in the coming weeks.”
Price and speed
Input and output tokens cost $4 and $20 per million, “20% less than Opus 5.” Cache reads cost $0.20 per million, “60% less than Opus 5.” Anthropic says the model “generates output more than 30% faster than Opus 5.” Fast mode, available in Claude Code and on the Claude Platform, offers “up to 2.5x speed” at $8 and $40 per million tokens.
Specifications
Anthropic’s model overview lists Claude Opus 5.5 with a 1M-token context window, 128K maximum output, adaptive thinking that is always on, a default effort level of medium, and a reliable knowledge cutoff of June 2026. It will not be retired before 22 September 2027. The API name is claude-opus-5-5.
Where it runs
The model is available “on all platforms, including Amazon Web Services, Google Cloud, and Microsoft Azure.” Anthropic also raised five-hour usage limits on its Pro, Max, Team and seat-based Enterprise plans.
Safeguards
Because the model is close to Anthropic’s most capable systems in biology and cybersecurity, it launches with safeguards similar to Claude Fable 5.1’s. Most cybersecurity tasks are re-routed to Claude Opus 4.8. It also launches with “preserved thinking,” an anti-distillation safeguard for API accounts created on or after 31 August 2026.
Claude Opus 5.5 Card Claims Checked Against Anthropic
We extracted every checkable statement from the card and compared it with Anthropic’s pages. The table lists the claims that matter most.
| Card says | Anthropic says | Verdict |
|---|---|---|
| Released 22 September 2026, first of the 5.5 family | Same | Correct |
| $4 input, $20 output per million tokens | Same, 20% below Opus 5 | Correct |
| Cache reads $0.20, cache writes $5 | $0.20 reads; $5 for 5-minute writes, $8 for 1-hour writes | Correct, incomplete |
| Fast mode up to 2.5x, $8 and $40 | Same, first-party API only | Correct, incomplete |
| Over 30% faster than Opus 5 | “More than 30% faster” | Correct |
| “40% less expensive than its predecessor” | 40% lower cost on typical workloads; list price 20% lower | Misleading without context |
| Context window of one million tokens (blurb) | 1M tokens | Correct |
| “Context window unspecified” (cons) | 1M tokens in the model docs | Wrong |
| Beats Fable 5.1 on all nine published benchmarks | Nine benchmarks; ahead of Fable 5.1 on all | Correct |
| Five benchmark rows quoted | All five figures match | Correct |
| First place on the Artificial Analysis index | Top score, 57.6 at max effort, on 24 September | Correct |
| Launched “about an hour” before GPT-6 Sol | About 90 minutes, per TechCrunch | Wrong |
| Higher session limits on paid plans | Five-hour limits raised on Pro, Max, Team, Enterprise | Correct |
| Stronger prompt injection defences | Matches or beats Opus 5 in every setting tested | Correct |
The score
Of the 14 claims in the table, nine are fully correct, two are correct but leave out a condition that changes the cost, one is misleading without context and two are wrong. For a card written within hours of launch, that is a better record than several we have checked. The problems are concentrated in a few places, and they are worth understanding.
Two Contradictions Inside the Claude Opus 5.5 Card
The most useful finding is not an error against Anthropic’s pages. It is two places where the card disagrees with itself.
The context window
The blurb at the top says Claude Opus 5.5 has “a context window of one million tokens.” Further down, the list of cons says: “Context window unspecified in the launch notes.” A bullet in the review then tells readers to check the “context window and knowledge cutoff” in the app.
What the documentation says
It is true that Anthropic’s launch post does not state the context window. But Anthropic’s model overview does: 1M tokens, with 128K maximum output and a reliable knowledge cutoff of June 2026. The blurb is right and the con is wrong. A reader who only scans the pros and cons would come away thinking the figure is unknown.
Free or paid?
The card is tagged Freemium and ends with a button reading “Try Claude Opus 5.5 for free.” Yet its own FAQ says that “inside the Claude apps, the model comes with the paid plans.” Anthropic’s launch post mentions higher limits on Pro, Max, Team and Enterprise plans only. The free label and the FAQ cannot both be the best guide for a reader deciding whether to pay.
One hour or 90 minutes?
The FAQ says Claude Opus 5.5 and GPT-6 Sol “launched the same day, about an hour apart.” TechCrunch put the gap at 90 minutes. AIxploria’s own GPT-6 Sol and Luna card, published half an hour earlier, also says “roughly 90 minutes.” Two cards in the same directory disagree about the same event.
The Benchmarks the Claude Opus 5.5 Card Leaves Out
The card reproduces five of Anthropic’s benchmark rows accurately. What it drops is the column that makes the picture less flattering.
Anthropic published nine rows and five competitors
Anthropic’s launch table compares Claude Opus 5.5 with Fable 5.1, Opus 5, GPT-6 Astra and GPT-5.6 Sol across nine benchmarks. The card shows only the three Anthropic models. The two OpenAI columns are gone.
The two rows Claude Opus 5.5 loses
With the OpenAI columns restored, Claude Opus 5.5 is not ahead everywhere. On Zapier’s AutomationBench, GPT-6 Astra scores 41.4% against 40.0%. On Terminal-Bench-Science, Astra leads 64.6% to 58.7%. Anthropic published both numbers itself. The card’s line that the model “beats Fable 5.1 on every benchmark” is true, but it answers a narrower question than a reader might assume.
| Benchmark | Opus 5.5 | Fable 5.1 | GPT-6 Astra | On the card? |
|---|---|---|---|---|
| Terminal-Bench 4.0 | 66.4% | 55.8% | 57.9% | Yes, without Astra |
| FrontierCode v1.1 | 54.4% | 50.3% | 53.3% | Yes, without Astra |
| CursorBench 4.0 | 57.8% | 51.8% | Not reported | Yes |
| GDPval-AA v2.1 (Elo) | 1,846 | 1,735 | 1,542 | Yes, without Astra |
| AutomationBench | 40.0% | 31.4% | 41.4% | No |
| Humanity’s Last Exam (tools) | 67.7% | 65.6% | 57.2% | No |
| Terminal-Bench-Science 0.1 | 58.7% | 52.6% | 64.6% | No |
| OSWorld 2.0 (partial credit) | 81.8% | 80.7% | Not reported | Yes, label dropped |
| Chartography (tools) | 89.0% | 88.4% | Not reported | No |
The “partial” label
Anthropic reports OSWorld 2.0 as “81.8% partial,” meaning partial credit on multi-step computer tasks. The card prints 81.8% without the qualifier. That matters, because some other published OSWorld 2.0 results use binary scoring, where a task counts only if it is completed in full.
Scores measured with safeguards on
Anthropic notes that Claude Opus 5.5 was evaluated “with its production safeguards enabled,” and that when they intervened, cybersecurity tasks were completed by Claude Opus 4.8 and some biology and AI development tasks by Opus 5. The company says this “likely reduces” its scores. The card does not mention it, although it is one of the more honest caveats in any launch this month.
What "40% Cheaper" Really Means for Claude Opus 5.5
The card’s blurb calls the model “40% less expensive than its predecessor.” The review says “40% cheaper than Opus 5.” Anthropic’s wording is more careful.
Two different 40s
Anthropic says the list price per token is 20% lower, and that “at default settings it will cost 40% less than Opus 5 on typical workloads.” The extra saving comes from Claude Opus 5.5 using fewer tokens per task. So “40% cheaper” is a claim about the cost of a typical job, not about the price list. For a task that uses as many tokens as it did on Opus 5, the saving is 20%.
Where the bigger cut is
The largest reduction is on cached input. Cache reads fall from $0.50 to $0.20 per million tokens, a 60% cut. Anthropic’s pricing page shows why: on Claude Opus 5.5, a cache hit costs 5% of the input price rather than the usual 10%. For agents that re-read the same long context over and over, this is the change that moves the bill.
Batch and fast mode
The card skips batch pricing. On Anthropic’s pricing page, Claude Opus 5.5 batch jobs cost $2 and $10 per million tokens, half the standard rate. Fast mode, which the card does cover, is available only on Anthropic’s own API, not on Claude Platform on AWS or other cloud platforms, and it cannot be combined with batch.
Claude Opus 5.5 Against GPT-6 Sol on Price
The card says OpenAI “countered with GPT-6 Sol and Luna at roughly half the API price.” That is true for most requests, but not all.
Short prompts
GPT-6 Sol costs $2 and $10 per million tokens, exactly half of Claude Opus 5.5’s $4 and $20. For a job of 150,000 input tokens and 15,000 output tokens, Opus costs $0.90 and Sol costs $0.45.
Long prompts
OpenAI’s pricing page shows that prompts over 272,000 input tokens are billed at a long-context rate: $4 input and $15 output for Sol. Anthropic charges the same rate across the full 1M context of Claude Opus 5.5. For a job of 400,000 input tokens and 40,000 output tokens, Opus costs $2.40 and Sol costs $2.20. The gap shrinks from 50% to about 8%.
| Job size | Claude Opus 5.5 | GPT-6 Sol | Sol saving |
|---|---|---|---|
| 150K input, 15K output | $0.90 | $0.45 | 50% |
| 400K input, 40K output | $2.40 | $2.20 (long-context rate) | 8% |
Tokens per task still decide it
Both companies argue that price per token is the wrong measure, because models use different numbers of tokens to finish the same task. Anthropic says Claude Opus 5.5 is unusually efficient. OpenAI makes the same claim for Sol. Nobody has yet published a head-to-head comparison on the same tasks, so the fairest test remains your own workload.
The Rank Badge: Claude Opus 5.5 Claims a Slot Grok 4.6 Holds
Every AIxploria card carries a rank badge. The Claude Opus 5.5 badge reads “#4 in LLM models” and links to the category page.
What is actually at number four
On 24 September, position four in AIxploria’s LLM models category was Grok 4.6, and Grok 4.6’s own card also says “#4 in LLM models.” The newer Grok 4.7 card, published two hours before the Claude Opus 5.5 card, also says “#4.” Three cards now claim the same position.
Is the badge a real ranking?
To test whether the badges mean anything, we opened six cards at known positions and read their badges. All six matched their slots exactly, from GPT-6 Astra at #1 to Gemini 3.8 Flash at #10. The badge is a working index of the category page. That makes a duplicate a real inconsistency, not a cosmetic one.
| Category position | Card in that slot | That card’s own badge |
|---|---|---|
| 1 | GPT-6 Astra | #1 |
| 2 | Claude Fable 5.1 | #2 |
| 4 | Grok 4.6 | #4 |
| 5 | Claude Opus 4.8 | #5 |
| 9 | Claude Opus 5 | #9 |
| 10 | Gemini 3.8 Flash | #10 |
| Not in first 36 | Claude Opus 5.5 | #4 |
Where Claude Opus 5.5 actually appears
Claude Opus 5.5 does not appear anywhere in the first three of the category’s 19 pages, which hold 36 models. Its predecessor Opus 5 sits at #9. We have seen this pattern before in the series, including a duplicate badge on the MAI-Transcribe-2 card in MAI-Transcribe-2 Has Just Landed on AIxploria.
Has Claude Opus 5.5 Reached AIxploria's Ranked Lists Yet?
A new card is one thing. Appearing in the directory’s curated lists, where most browsing readers look, is another.
Today’s reading
We counted mentions of Claude Opus 5.5 on the Top 100 page and the Ultimate List. Both returned zero. The model appears only on the “latest AI” page, which lists every new card. That is normal for a card only seven hours old.
What earlier cards tell us
GPT-6 Astra’s card went live on 6 September and still scored zero on both lists eight days later. On 24 September it returned 20 mentions on the Top 100 and 10 on the Ultimate List. On the Top 100 page, those mentions sit in the trending panel at the top, not in the ranked list itself. We covered that card in GPT-6 Astra Is Now Available on AIxploria.
What that means for readers
Readers who browse the ranked lists this week will not find Claude Opus 5.5, even though it tops the Artificial Analysis index. Directory lists lag the market, sometimes by weeks. For current model choices, go to the vendor’s documentation or an independent leaderboard.
What the Claude Opus 5.5 Card Gets Right
It would be unfair to list only the faults. On the facts most readers need, the card is solid.
Prices and benchmarks are accurate
Every price in the review matches Anthropic’s pricing page, and every benchmark figure matches Anthropic’s launch table. The card even includes cache writes and fast mode, details several news reports skipped.
It flags vendor benchmarks as vendor benchmarks
The review says the scores are “best read as vendor numbers until independent testing settles the debate.” That is exactly the right warning. It also notes that Anthropic itself says the gap with Fable 5.1 is “narrower than these scores suggest.”
It covers the writing change
Anthropic says Claude Opus 5.5 puts “the most important information up front” and uses less jargon. The card explains this clearly, with a practical example of turning a messy Slack thread into three readable bullet points.
Should You Use Claude Opus 5.5?
For most teams already using Anthropic’s models, the answer is yes, at least as a test. Anthropic’s own overview tells developers unsure which model to use to “start with Claude Opus 5.5 for most workloads.”
Who gains most
Teams running long coding agents gain from the lower cache price and fewer tokens per task. Anthropic cites an early tester who audited and fixed a 200,000-line codebase in under three hours, where Opus 5 took over 20 hours. Anyone paying for Claude subscriptions gains from the higher five-hour limits.
Who should stay on Fable 5.1
Anthropic still recommends Claude Fable 5.1 “for demanding reasoning and long-horizon agentic work.” If your evaluations show Claude Opus 5.5 falling short at high effort, Fable remains the fallback, at $10 and $50 per million tokens.
Watch the safeguards
If your work touches security research or biology, expect some requests to be handled by Opus 4.8 or Opus 5 instead. Anthropic’s cybersecurity safeguards re-route most security tasks, and Anthropic says verified practitioners will soon be able to use the model through its Cyber Verification Program. Our AI models and tools hub tracks these changes as they happen, and our guide to the Claude 5 family covers the wider line-up.
Frequently Asked Questions About Claude Opus 5.5
What is Claude Opus 5.5?
Anthropic’s newest Opus model, released on 22 September 2026 as the first of the Claude 5.5 family. Anthropic says it performs at the level of Claude Fable 5.1 on most work and costs 40% less to run than Opus 5 on typical workloads.
How much does Claude Opus 5.5 cost?
$4 per million input tokens and $20 per million output tokens, with cache reads at $0.20. Batch jobs cost half. Fast mode costs $8 and $40.
What is the Claude Opus 5.5 context window?
1M tokens, with up to 128K output tokens, according to Anthropic’s model overview. The AIxploria card’s cons list wrongly says it is unspecified.
Is Claude Opus 5.5 free?
The AIxploria card is tagged Freemium, but its own FAQ says the model comes with paid Claude plans. Anthropic’s launch post only mentions paid plans.
Is the AIxploria rank badge accurate?
No. The card says “#4 in LLM models,” but position four belongs to Grok 4.6, and Claude Opus 5.5 does not appear in the first 36 places of that category.
Does Claude Opus 5.5 beat GPT-6 Astra?
On four of the six benchmarks where Anthropic lists an Astra score, yes. GPT-6 Astra leads on AutomationBench and Terminal-Bench-Science.
References
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