infochanged

Workers - Preserve exception details in console logs

Announced: 2026-08-24
Tags: Workers
Severity: info, set by reef/rss-rule-v1
Source: https://developers.cloudflare.com/changelog/post/2026-08-24-preserve-exception-info/

Console methods now preserve exception details in your Worker's logs. When your Worker logs an exception, the corresponding log entry includes the exception name, message, and stack. For example, your Worker can catch and log an exception: <div><div data-nb-tabs data-nb-sync-key="workersExamples" class><div class="relative flex border-b border-border" role="tablist" data-nb-tabs-list></div><div class="mt-3"><div role="tabpanel" data-nb-tabs-content data-nb-tab-label="JavaScript" class><figure class="nb-code-figure" data-nb-lang="js"><pre class="astro-code astro-code-themes github-light github-dark nb-shiki-c6xiwz" tabindex="0" data-language="js" data-nb-lang="js"><code>try { throw new Error("Deliberately created exception"); } catch (error) { console.error("caught exception:", error); }</code></pre></figure></div><div role="tabpanel" data-nb-tabs-content data-nb-tab-label="TypeScript" class><figure class="nb-code-figure" data-nb-lang="ts"><pre class="astro-code astro-code-themes github-light github-dark nb-shiki-c6xiwz" tabindex="0" data-language="ts" data-nb-lang="ts"><code>try { throw new Error("Deliberately created exception"); } catch (error) { console.error("caught exception:", error); }</code></pre></figure></div></div></div><script type="module" src="https://developers.cloudflare.com/home/runner/work/cloudflare-docs/cloudflare-docs/src/components/ui/tabs/Tabs.astro?astro&type=script&index=0&lang.ts"></script></div> If you use <a href="https://developers.cloudflare.com/workers/observability/">Workers Observability</a>, your log is automatically enriched with structured error information. The following example shows how the enriched log appears in the Cloudflare dashboard: <img src="https://developers.cloudflare.com/cdn-cgi/image/onerror=redirect,width=1200,height=212,format=webp/_astro/2026-08-24-error-info.Be4rAN4i.png" alt="Workers Observability log entry showing a caught exception and its stack trace" loading="lazy" decoding="async" width="1200" height="212"> The exception's stack trace appears directly in the log message. If you send telemetry to a <a href="https://developers.cloudflare.com/workers/observability/logs/tail-workers/">Tail Worker</a>, the Tail Worker now receives a log entry with an <code>errorInfo</code> array: <figure class="nb-code-figure" data-nb-lang="json"><pre class="astro-code astro-code-themes github-light github-dark nb-shiki-c6xiwz" tabindex="0" data-language="json" data-nb-lang="json"><code>{ "message": ["Request failed:", "RangeError: Value out of range"], "errorInfo": [ null, { "name": "RangeError", "message": "Value out of range", "stack": "RangeError: Value out of range\n at ..." } ], "level": "error", "timestamp": 1784851200000 }</code></pre></figure> Each <code>errorInfo</code> item corresponds to the console argument at the same index in <code>message</code>. Arguments that are not exceptions have a <code>null</code> entry.

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