Claude Opus 5.5 vs GPT-6 Astra: Check This Before You Switch

0:00 You're paying for GPT6 Astra and it's doing fine. Then a headline lands. Claude takes the top spot. Artificial analysis puts Claude Opus 5.5 at 58 on its intelligence index and Astra at 53.

0:13 Now your cursor is hovering over a pricing page. Does that fivepoint gap make Claude the better coding partner on its own? No. The 58 is real, but most of that index isn't measuring coding. On

0:25 the coding test that matters most here, the two are basically tied. And the most useful result in the whole comparison is a cheaper opus setting matching Astra's best run for a lot less money. Three

0:37 decisions really fixing a hard bug, understanding a big codebase, finishing the work without torching your budget. And then there's that effort knob. Gray stamp means artificial analysis and

0:48 independent benchmarking group. Anthropic stamp means it's the vendor talking. First, what's inside that 58? It's one score across 10 evaluations, and plenty of them aren't coding at all.

0:58 a brutal academic exam, office style work tasks, legal and finance questions. Both numbers also come from max effort, the setting where each model thinks longest and spends the most tokens

1:09 before it answers. Opus leads on six of the 10. It's behind on three and the one worth remembering is AALCR, artificial analysis's long context reasoning test. It comes back when we get to big code

1:22 bases. Artificial analysis's own word for the agent tests is parody. That covers terminal bench 4.0 zero and automation bench. So top spot is true for the total on the agent tests. It's a

1:34 tie. 6 out of 10 is a good season. It isn't a sweep. That's why the overall gap is a weak signal for coding. Your failing test doesn't care how a model handles a finance question. So hard bugs

1:46 first. The closest evidence here is terminal bench 4.0, the terminal coding test. Artificial analysis has Opus 5.5 at 59.6%. Astra at its extra high setting called X

1:58 high scores 59 6/10 of a point apart. Artificial analysis describes Opus as level with Astra and that's the right read. If fixing tough bugs is your reason to switch, the independent number

2:10 doesn't hand you one. Enthropic launch page tells the same story from the cost side. Its line is that Opus matches Astra for about 40% of the cost. Same score, smaller bill. That's the pitch.

2:21 Now read the footnote. Enthropic ran opus at X high and Astra at high one notch lower. Artificial analysis compared against Astra at X high. So the two charts aren't pairing the same

2:32 settings. The chart gets the big font. The effort levels get the small print. So on bugs, the independent result is a draw. I'd hold anthropics 40% loosely. It's the vendor's number. On settings

2:43 that don't line up with the independent test. Decision two, a big code base. The spec that stands out is Opus 5.5's context window. The amount of text it can hold in view at once, 1 million

2:55 tokens. That's room for a good chunk of a service, tests, and config included in a single session. But fitting a repo in the window and reasoning well about it are different skills. The nearest

3:06 independent signal is AALCR and Opus trails Astra there. One caveat, AALCR tests long documents, not code navigation, so take it as a hint. Astra has something more direct on Sweet Atlas

3:20 Q&A. It scores 62%. That's 124 questions from scale AI where the model has to explore a codebase and explain how the code behaves and why an issue happens. For comparison, GPT 5.6 Soul scored 54.

3:34 So this isn't a head-to-head. Astra has shown its work on code understanding. There's no published opus score on the same exam to set beside it. So that slot stays empty. Anthropic's big codebase

3:45 evidence is one story. One tester completed a 680 line code migration in less than a day. That's a serious job. It's also a sample size of one told by the company selling

3:57 the model. So for big code bases, I'd lean Astra lightly. It has a relevant published score and opus trails on the closest long context test. The evidence is thin on both sides which makes this

4:09 the least settled of the three. Decision three, budget. Start with the price sheet. Opus 5.5 is $4 per million input tokens and $20 per million output. Astra is $10 and $50 per token. Opus costs 40%

4:25 of Astra's rate. Different 40% from Anthropic's chart. By the way, this one's just the price list. That looks like it settles things until you watch the meters. At max effort on artificial

4:36 analysis's evals, Opus writes about 119,000 output tokens per task. Astra writes about 27,000. So per task, the order flips. Opus at max, $5.98. Astra at max, $326.

4:52 Opus is cheaper per token and pricier per job. It's the contractor with the lower hourly rate who bills four times the hours. Astra gets to 53 on roughly a quarter of the output tokens Opus spends

5:03 getting to 58. That fivepoint lead is written in a lot of tokens. A caveat on every dollar figure here. Cost per task is artificial analysis measuring its own test set. Your real bill depends on

5:15 caching. Your harness, prompt length, and how often the agent retries. Use these numbers to compare, not to budget. If the story ended there, budget would go to Astra. At max, it's five points

5:27 behind and cost a little over half as much per task. Now, turn the knob. Drop Opus from max to high and watch the bill per task shrink. At high, Opus scores 54 on the same index for $182 a task. Set

5:41 that next to Astra at max 53 for $326. Opus at high is a point ahead and costs about 56% as much. Scale that to a 100 of artificial analysis tasks. About $598,

5:56 $326 and $182. Same ratio, easier to feel. So, the model that lost the budget round at max matches Astra's top run from two notches down. It's a point higher even for a little over half the

6:09 cost. Picking an effort level can matter as much as picking a model. Watch the score bar in the cost meter as the knob climbs from high back to max. The score bar moves four points. The cost meter

6:20 jumps about $4 a task. That's more than triple the price for those last four points. Keep turning this time downward. At medium, which is Opus' default, it scores 51 for $1.34 a task. That's two

6:33 points under Astra at max. So, the default on its own doesn't win this. Astra goes cheap, too. At low, it's 82 cents a task. Its index score at low isn't published here, so that bar is

6:45 just an outline. Artificial analysis also draws a frontier on its cost versus score charts. That's the line where nothing buys you a higher score for less money. In its reports, every Astra

6:56 effort level sits on that line. And four of Opus' five due two. Those are separate charts, though. Put both ladders on one chart, and Opus at high pushes Astra's max off the line because

7:06 it scores a point higher for less. So, each ladder is mostly well built on its own. Line them up against each other, and the rung that stands out is Opus at high. If you're already on Claude,

7:17 Anthropic adds one more claim. Opus 5.5 at default effort beats Opus 5 at max for about a fifth of the cost. Vendor stamp on that one, but it points the same way. The top setting isn't

7:29 automatically the one to run. Back to the three decisions. Hard bugs, a tie on terminal bench, 59.6 to 59. Big code bases, a light lean to Astra on thin evidence. Budget. Astra wins at max, but

7:43 Opus at high matches Astra's max score a point up for about 56% of the cost per task. If you're on Astra and it's handling your bugs and your repo fine, that 58 isn't a reason to switch. The

7:55 lead comes from a mostly non-coding index and the coding test that counts is a tie. If you're running Astra at max and the bill is what hurts, try Opus 5.5 at high on your own tickets. On this

8:07 index, it's a point higher for a little over half the cost per task. That's a price signal, not a bug fixing guarantee and set it to high yourself. The default is medium and medium lands under Astro's

8:18 max. If you do trial it, keep it simple. Take a week of real tickets, run Opus at high, and track two things: how many it closes and what each one costs. That's the question the leaderboard can't

8:29 answer for you. And if your days are mostly spent figuring out how a huge unfamiliar codebase works, I'd stay on Astro for now. It's the one with a published score on that exact kind of

8:39 question. One question these numbers leave open. Astra's index scores below max aren't in this comparison. Its cheaper settings go as low as 82 cents a task. If one of them lands within a

8:51 point or two of 54 for well under $182, the budget call gets close again. That's the number I'd want before switching anything.