Claude Haiku 5.5 vs Aion 3.5: Thirty Times the Input Price for a Model Nobody Has Scored

Claude Haiku 5.5 lists at $0.10 per million input tokens. Aion 3.5 lists at $3.00. That is thirty times the input price and twelve times the output price for two models that both accept a long text prompt and return text, and the gap is not explained by capability — it is explained by what each company is selling. Claude Haiku 5.5, released October 7, 2026, is a commodity-priced workhorse with an effort dial and an independent score. Aion 3.5, released September 23, 2026 by AionLabs, is a mandatory-reasoning ensemble that comes in two sizes, one of which is genuinely cheap. Whether the thirty-times premium is worth paying depends entirely on a question the vendor has not answered.

Here is the uncomfortable part up front: Artificial Analysis has scored Claude Haiku 5.5 and has never published a score for Aion 3.5. Neither has anyone else we can find. So this is not a comparison of two measured things. It is a comparison of one measured thing against one set of vendor claims, and the honest way to write it is to say so in every section rather than once in a footnote.

The two models, in one paragraph each

Claude Haiku 5.5 is the vendor's small model, ID claude-haiku-5-5, text and image in and text out, with a 1M-token context window, a 128,000-token maximum output (300,000 with a beta header on the Batch API), a June 2026 training cutoff and an Anthropic commitment not to retire it before October 7, 2027. Effort is adjustable across Low, Medium, High, Xhigh and Max, defaulting to Medium, with adaptive thinking on by default. Cache reads cost $0.01 per million tokens. Above 100,000 tokens of prompt, both the input and output rates multiply by five.

Aion 3.5 is AionLabs' flagship, ID aion-labs/aion-3.5, and it is text-only in both directions. Context is 262,144 tokens — doubled from Aion 3.0's 131,072 — with a 32,768-token maximum output. Reasoning is mandatory rather than optional, with a default of high that can be moved to max or down to low. Architecturally it is described as a multi-model ensemble in the GLM family rather than a single trained network, which is the most interesting thing about it and also the hardest thing to verify from outside. It is priced at $3.00 per million input tokens, $0.75 for cached input and $6.00 for output, flat across the whole window. Aion 3.5 Mini, launched the same day, is $0.70 / $0.18 / $1.40 for the same 256K context — and that smaller sibling is the one that makes this matchup interesting.

• The dimensions, one line each

• Input price — Claude Haiku 5.5 $0.10 per million up to 100K tokens, rising to $0.50 above it; Aion 3.5 $3.00 flat across the whole 256K window.

• Output price — Claude Haiku 5.5 $0.50 per million to 100K then $2.50; Aion 3.5 $6.00 flat.

• Cached input — Claude Haiku 5.5 $0.01 per million on reads and $0.125 on five-minute writes; Aion 3.5 $0.75 on cached input, with no separately published read rate.

• Context window — 1,000,000 tokens against 262,144.

• Maximum output — 128,000 tokens against 32,768.

• Input modalities — text and images against text only.

• Reasoning control — a five-position effort dial from Low to Max against three positions where high is the default.

• Independent score — Artificial Analysis Intelligence Index 43 with a Max configuration at 43.40, second of 182 models; none published for Aion 3.5.

• Cost per finished task — $0.21 per Artificial Analysis index task for Claude Haiku 5.5; not measurable for Aion 3.5 without a score.

• Output speed — 243.4 tokens per second for Claude Haiku 5.5; unreported for Aion 3.5.

Why the flat rate is not the win it looks like

Aion 3.5's flat $3.00 across 256K is the cleanest thing about its pricing, and it is a direct answer to the awkwardness on Anthropic's side: a prompt that grows from 99,000 to 101,000 tokens costs five times more per token, which forces you either to stay well under the line or to give up on the cheap band entirely. Aion 3.5 has no line. You can send 240,000 tokens and pay the same per-token rate you would pay for 4,000.

That advantage evaporates the moment you do the arithmetic on a real workload. A 240,000-token call on Aion 3.5 costs about $0.72 in input; the same call on Claude Haiku 5.5 above the threshold costs about $0.12. Even paying the penalised post-100K rate, Haiku 5.5 is roughly six times cheaper on the largest prompt either model can take. The flat rate removes a cliff, not a cost.

Where flat pricing genuinely does help is predictability. A pipeline whose prompt size drifts between 80,000 and 130,000 tokens is miserable to budget on a tiered scheme and trivial on a flat one, and if that is your shape, Aion 3.5's flatness is worth something even before capability enters the conversation.

The case for Aion 3.5, stated as strongly as the evidence allows

Three arguments hold up. First, mandatory reasoning at a high default means less prompt engineering: there is no effort parameter to tune and no risk of a low setting quietly degrading a task nobody re-tested. Second, an ensemble in the GLM family is a genuinely different failure profile from a single Anthropic small model, and if you are already running Claude Haiku 5.5 across a large surface, an uncorrelated second opinion has value even at thirty times the input price — you would route to it rarely. Third, Aion 3.5 Mini at $0.70 / $0.18 / $1.40 with the same 256K context is a credible cheap tier, and any comparison that only looks at the flagship is comparing the wrong Aion model.

What does not hold up is treating the thirty-times premium as evidence of thirty times the capability. AionLabs publishes no benchmarks for Aion 3.5 that we can find, no independent lab has scored it, and the ensemble claim has no public eval attached to it. A vendor that has a stronger model than Claude Haiku 5.5 and can demonstrate it would demonstrate it.

Where Claude Haiku 5.5 wins outright, and it is not close

Image input, for one. Aion 3.5 is text-only, and Claude Haiku 5.5 takes images, which decides any document, screenshot or diagram workload before pricing is mentioned. Maximum output, for another: 128,000 tokens against 32,768, with a 300,000-token beta path on Batch. And the effort dial, which is a cost-control mechanism rather than a capability: at Low, Claude Haiku 5.5 produces far fewer reasoning tokens, and since reasoning bills as output, that is where you keep a verbose agent inside the cheap band.

The independent score is the last word on this. On Artificial Analysis' index, Claude Haiku 5.5 sits at 43 overall and 43.40 in its Max configuration, second of 182 models, at $0.21 per index task with 243.4 tokens per second of output. Those are independently run numbers. Aion 3.5 has none, and until it does, the comparison the buyer is actually making is "a model with a published score and a price I can predict" against "a model with a higher price and no score," which is not a hard call for a production path.

Running both without doubling the plumbing

Aion 3.5 is reachable through AionLabs' own API and several third-party platforms. Claude Haiku 5.5 is available through Anthropic's API and, from there, wherever Anthropic's models are resold. Neither is on OrcaRouter's catalogue today, and we will not imply otherwise: what we route from this corner of the market is anthropic/claude-haiku-4.5, anthropic/claude-sonnet-5.5, anthropic/claude-opus-5.5 and anthropic/claude-fable-5.1 — the tier above the model this article is about.

The reason it matters here is that the sensible architecture for this matchup is a small share of traffic on the expensive model. You do not move a pipeline to a $3.00-per-million ensemble; you send it the two per cent of calls where a second opinion is worth $3.00, and you keep everything else on the cheap model. That means two providers, two keys and two billing surfaces for a two per cent workload, which is exactly the shape a gateway is for. OrcaRouter passes provider list price through at 0% markup, so a vendor price change is live the same day rather than on a repricing cycle, and the A/B is a model string rather than a second integration. Where neither leg is on our catalogue, the honest answer is that we are the wrong layer for it and a direct integration is what you want.

What would settle this

One independent evaluation of Aion 3.5. That is the whole missing piece. If a neutral lab scores it anywhere near Claude Haiku 5.5's 43 at $0.21 per task, then AionLabs is charging thirty times the input price for parity and the ensemble story is a liability rather than a feature. If it scores materially higher, then the premium is real and the right move is to spend it on the small fraction of calls that need it. Until the number exists, a buyer choosing between these two is choosing a measured model at a published price or an unmeasured one at a higher one — and there is only one defensible default in that pair.

That means two providers, two keys and two billing surfaces for a two per cent workload, which is exactly the shape a gateway is for.