Adzuna vs Upwork

Adzuna's job-search API exposes its aggregated listings, salary histograms, and regional/company vacancy trends across dozens of countries. Access requires a free app_id/app_key pair from its developer portal, with results returned as JSON, JSONP, or XML.

Upwork's public API is now a single GraphQL endpoint covering the freelance marketplace it once exposed as separate REST resources — job postings, proposals, contracts, time tracking, and messaging — authenticated via OAuth 2.0 (Authorization Code Grant with PKCE). A live probe confirmed the stored docs URL still redirects to the current GraphQL reference and that the gateway itself returns a genuine 401 challenge to unauthenticated calls, with no Access-Control-Allow-Origin header on either that request or a follow-up preflight. Registering an application is free, gated only by Upwork's own review and a 300-request-per-minute-per-IP rate limit.