Pricing: Metals.dev opens far cheaper
A $1.79/mo entry plan against $19.99/mo is a wide gap for anyone testing a metals feed before committing budget. The gap widens at production, $39.99/mo for 100,000 requests on Metals.dev against $149.99/mo on Metals-API, but Metals.dev still comes out cheaper at both ends in the figures each provider publishes.
The overage behavior differs too. Metals-API auto-bills past quota. Metals.dev's page frames its overage handling as a plan-based quota instead, a distinct policy rather than a synonym for the same thing.
Naming the source behind the number
Metals.dev is the more specific of the two about where its prices come from: it names LBMA, LME, MCX, and IBJA as blended inputs, though it doesn't publish the blend weights or per-source attribution on individual responses. Metals-API's own comparison page makes no equivalent claim about a specific benchmark authority, so that traceability advantage sits with Metals.dev based on what's actually published.
Coverage and freshness
Both list broad currency support at 170+. Metals.dev additionally lists platinum and palladium, which Metals-API's own page doesn't specifically address even while claiming broad industrial-metals breadth elsewhere. Metals.dev also publishes concrete freshness and history figures, up to a 60-second delay on real-time data and 5+ years of history capped at a 30-day window per request, where Metals-API's page stays general (historical and time-series data) without matching detail.