Longest URL the engine sends as a GET. A longer request (a where with a long
IN (…) list) goes out as a form-encoded POST to the same path instead: the
ArcGIS Online front end answers a GET URL of about 2.9 KB with a misleading
HTTP 404 and one above about 20 KB with 414, while /query takes the same
parameters as a POST body (live-checked 2026-09-26). 2,000 characters stays
well below the point where the GET starts to fail.
Longest URL the engine sends as a GET. A longer request (a
wherewith a longIN (…)list) goes out as a form-encoded POST to the same path instead: the ArcGIS Online front end answers a GET URL of about 2.9 KB with a misleading HTTP 404 and one above about 20 KB with 414, while/querytakes the same parameters as a POST body (live-checked 2026-09-26). 2,000 characters stays well below the point where the GET starts to fail.