Shipzil checks the USPS API every 5 minutes across EasyPost, Shippo, ShipStation and ShipEngine — four platforms run by three independent companies — and sends its own production rate request to each platform. Across 155 carrier-affecting incidents recorded here, 91% were reported by only one company, so a problem on a single platform usually means that platform's USPS integration rather than USPS itself. Snapshot at November 11, 2026, 03:55 UTC: USPS API status: 4 operational across 4 monitored platforms. Last resolved incident: November 11, 2026. Over the last 90 days the worst-performing platform for USPS was Shippo, at 94.60% reported uptime. The status below refreshes live.
Where a platform published component state changes, the window is measured from those —
when each component actually left and returned to operational. Otherwise it falls back to
when the incident was opened and closed, which overstates it. Either way this is uptime
as reported by the platforms, not independently measured: there may be outages nobody
reported. Account-surface incidents and standing advisories are excluded, since neither
is carrier API downtime.
Of the 155 carrier-affecting incidents behind these figures, 45 (29%) had their carriers inferred from the incident title rather than a component the platform tagged. And a platform that reports less looks better here: Shippo 79, EasyPost 42, ShipEngine 25, ShipStation 9 incidents recorded respectively.
Reports no USPS incidents in 90 days, but did not answer 8 of our rate checks in the last 24h — a failure it did not report, not a declared outage.
Measured reachability
Shipzil's own rate checks rather than a platform report: how often a request to each platform returned at least one bookable USPS rate. Only platforms whose monitoring account can quote USPS appear.
A check the platform never answered is excluded from these counts rather than charged to USPS — which is why a platform with unanswered checks shows a smaller total than the rest. Those are the platform's own failures and are listed on its page. Percentages are withheld below 20 checks.
Platform-reported API response time, 24h
Published by the platform about its own API, not measured here and not specific to USPS. Shipzil's own measurement of a USPS rate request through each platform is in Measured reachability above, and is typically several times larger because it includes the carrier call. A platform that stops publishing keeps its last reading for up to two hours before it is dropped, so each row states when it was last published.
USPS API status is checked every 5 minutes against 4 shipping platforms run by three independent companies, plus an independent rate request to each. 91% of carrier-affecting incidents recorded here were reported by only one company, so a lone report usually points to that platform's integration rather than the carrier. Shipzil also records production rate failures even when the platform files no incident. The current reading is at the top of this page and refreshes without reloading.
How is USPS API status determined?
Two separate signals. What each platform reports about USPS on its own status page, across EasyPost, Shippo, ShipStation, ShipEngine; and Shipzil's own rate request to each platform's production API every 5 minutes, recording whether USPS returned a bookable rate. The two are never merged: a platform reporting operational while our request fails is evidence, not a contradiction to resolve.
Is USPS down, or is it my shipping platform?
Compare the platforms. If only one of EasyPost, Shippo, ShipStation or ShipEngine reports a USPS problem, the fault is most likely that platform's USPS integration; if platforms from two or more independent companies report it together, it is more likely USPS itself. ShipStation and ShipEngine are both run by Auctane, so together they count as one source. Of 155 carrier-affecting incidents recorded here, 91% were reported by only one company. Shipzil's own rate checks add a third signal: a failure it measured that no platform reported.
What is USPS API uptime?
USPS reported 90-day uptime is 94.60% on its worst-performing platform (Shippo). Shipzil reports the worst platform rather than an average, because averaging mixes different integrations and improves the number every time a platform is added. This is uptime as reported by those platforms, not independently measured.