Elevated errors on multiple Claude models (Haiku 4.5, Sonnet 5)

Anthropic reported elevated errors on several models including Haiku 4.5 and Sonnet 5. The Haiku 4.5 incident progressed from investigating to monitoring, while the Sonnet 5 incident was resolved. A new incident for elevated errors on several models was also identified and is being fixed.

Jul 21, 2026Views:0

Impact Assessment

Cost0

Reliability4

Migration0

Quality2

Compliance0

Elevated errors affect reliability and may degrade output quality for affected models. No cost or migration impact.

Changes

Before

Elevated errors on Haiku 4.5 | https://status.claude.com/incidents/j0y67nj6w93z | &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;21&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;14:44&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Identified&lt;/strong&gt; - The issue has been identified and a fix is being implemented. &lt;/p&gt; &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;21&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;13:22&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Monitoring&lt;/strong&gt; - A fix has been implemented and we are monitoring the results. &lt;/p&gt; &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;21&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;13:14&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Identified&lt;/strong&gt; - The issue has been identified and a fix is being implemented. &lt;/p&gt; &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;21&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;13:04&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Investigating&lt;/strong&gt; - We are currently investigating this issue. &lt;/p&gt;
Elevated error rates for Sonnet 5 | https://status.claude.com/incidents/lj0khk5vd7v7 | &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;17&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;18:27&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Resolved&lt;/strong&gt; - This incident has been resolved. &lt;/p&gt; &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;17&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;18:22&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Monitoring&lt;/strong&gt; - A fix has been implemented and we are monitoring the results. &lt;/p&gt; &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;17&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;18:13&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Update&lt;/strong&gt; - We are continuing to investigate this issue. &lt;/p&gt; &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;17&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;18:12&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Investigating&lt;/strong&gt; - We are currently investigating this issue. &lt;/p&gt;

After

Elevated errors on several models | https://status.claude.com/incidents/vcynh9cf33xp | &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;21&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;15:51&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Identified&lt;/strong&gt; - The issue has been identified and a fix is being implemented. &lt;/p&gt; &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;21&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;15:35&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Investigating&lt;/strong&gt; - We are currently investigating this issue. &lt;/p&gt;
Elevated errors on Haiku 4.5 | https://status.claude.com/incidents/j0y67nj6w93z | &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;21&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;15:30&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Monitoring&lt;/strong&gt; - A fix has been implemented and we are monitoring the results. &lt;/p&gt; &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;21&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;14:44&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Identified&lt;/strong&gt; - The issue has been identified and a fix is being implemented. &lt;/p&gt; &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;21&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;13:22&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Monitoring&lt;/strong&gt; - A fix has been implemented and we are monitoring the results. &lt;/p&gt; &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;21&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;13:14&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Identified&lt;/strong&gt; - The issue has been identified and a fix is being implemented. &lt;/p&gt; &lt;p&gt; &lt;small&gt;Jul &lt;var data-var=&apos;date&apos;&gt;21&lt;/var&gt;, &lt;var data-var=&apos;time&apos;&gt;13:04&lt;/var&gt; UTC&lt;/small&gt;&lt;br&gt; &lt;strong&gt;Investigating&lt;/strong&gt; - We are currently investigating this issue. &lt;/p&gt;

Sources

status

Anthropic Status History

Elevated errors on several models | https://status.claude.com/incidents/vcynh9cf33xp | <p> <small>Jul <var data-var='date'>21</var>, <var data-var='time&ap...

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