Head-to-head comparison
GPT X2.5 135M (AxiomicLabs) and Seed 1.6 Flash (ByteDance Seed) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.
Snapshot as of 17 August 2026
As of 17 August 2026, GPT X2.5 135M holds the stronger ModelCap Index position (#118 vs #121); and GPT X2.5 135M ships open weights.
Evidence: global corpus prior · leave-one-anchor-out calibrated · global corpus prior · leave-one-anchor-out calibrated. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.
Neither model has a published result on a public benchmark board ModelCap tracks yet.
Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.
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GPT X2.5 135M ranks higher on the ModelCap Index as of 17 August 2026: #118 against #121. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it.
At least one of the two has no listed API price on ModelCap right now, so no price comparison is made.
Both publish a —-token context window.
The two models do not share a coding benchmark board on ModelCap yet, so no head-to-head coding score is published; the ModelCap Index position is the closest overall signal.
GPT X2.5 135M: Open weights. Seed 1.6 Flash: API only. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.
ModelCap currently lists 0 API providers for GPT X2.5 135M and 1 for Seed 1.6 Flash, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.
Every figure comes from the sealed ModelCap dataset published 17 August 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.