AionLabs: Aion-2.0 vs ByteDance Seed: Seed 1.6

AionLabs: Aion-2.0 is a text model from AionLabs, released on 2026-02-23. ByteDance Seed: Seed 1.6 is a text model from ByteDance Seed, released on 2025-12-23. Both are served through api14 under the text category, and both accept a text prompt and return text. That shared shape matters, because it means the choice between them is not about whether they can do the job at all, but about which one fits the specific job you have in mind.

The clearest split is context and input modalities. Seed 1.6 has the larger context window, 262144 tokens against 131072 for Aion-2.0, so it can hold roughly twice as much material in a single call. Seed 1.6 also accepts image and video input alongside text, while Aion-2.0 accepts text only. On structured output, Seed 1.6 is the one that supports it; Aion-2.0 does not list structured_outputs among its parameters. Both expose reasoning controls and tool calling, so neither has an edge there. On price, the two are not aligned: Seed 1.6 is the cheaper option on input, while Aion-2.0 is the cheaper option on output. The live price table on this page shows the actual numbers, so check it before you commit to a high volume workload.

For day to day work, that combination points in a fairly practical direction. If your task is text in and text out, and the output side dominates your token spend, Aion-2.0 is worth a look because its output pricing is the lower of the two. If you need to feed in screenshots, scanned pages, video frames or any other non text material, Seed 1.6 is the only one of the pair that can take it. The same goes if you need a schema constrained response, since structured outputs are only available on Seed 1.6. And if you are working with long documents, large codebases or extended conversation histories that would otherwise need chunking, the larger context on Seed 1.6 lets you skip some of that plumbing.

Calling either model is the same operation. api14 exposes an OpenAI compatible API, so you point your existing client at the gateway, send your request to the chat completions endpoint, and set the model field to the id you want. Use "aion-labs/aion-2.0" for Aion-2.0 and "bytedance-seed/seed-1.6" for Seed 1.6. Everything else in the request body stays as it is: your messages, your temperature, your max_tokens, your tools. Switching between the two is a one line change to the model id, which makes it cheap to benchmark both against your own traffic rather than guessing from a comparison page.

There are still cases where the other model wins. If you are doing pure text work with heavy output, Aion-2.0 is the better pick on cost, and its 131072 token context is generous for most single document or single session tasks. Conversely, if your input is text only but you need structured outputs, Seed 1.6 is the one to call, since that parameter is not available on Aion-2.0. Neither model is strictly better; the deciding factors are whether you need image or video input, whether you need structured output, how much context you need, and which side of the token bill is larger for your workload.