Stack Trace Analyzer

The Stack Trace Analyzer turns a pasted error trace into a structured summary: the exception type and message, the runtime, the top frame, the first frame in your own code and the full chain of causes. It reads JavaScript, Node.js, Python, Java and other JVM languages, Go, PHP, Ruby and C# / .NET traces, and works entirely in your browser.

1. 1.Paste a stack trace, traceback or panic, or load an example.
2. 2.Check the detected runtime, or choose it yourself if the guess is wrong.
3. 3.Optionally list your application path or package prefixes so your own frames are recognized reliably.
4. 4.Read the summary and the error chain, then inspect the frames: filter by category or collapse runtime and dependency frames.
5. 5.Copy a frame, a location or the whole summary as Markdown for a ticket or chat.

Java `Caused by:` and `Suppressed:` blocks, Python "During handling of the above exception" and "direct cause" chains, Node.js `[cause]` blocks and AggregateError groups, PHP previous exceptions, Ruby causes, Go panics with other goroutines and .NET inner exceptions are shown as one chain. The root cause is the deepest cause, which is usually where the problem started.

Frames are grouped as application, framework, dependency, runtime or unknown from paths and package names such as node_modules, site-packages, vendor, java.base or System. Each category shows how strong the evidence is. A rule can be wrong for unusual layouts, so add your own prefixes when it matters. This is deterministic pattern matching, not an AI diagnosis.

Traces can contain internal paths, hostnames and data, so they are analyzed only in this tab: nothing is uploaded, stored or added to the URL. Only the optional prefix list is remembered on this device. Traces up to 1 MB are supported, traces over 200 KB are analyzed in the background, and at most 2,000 frames are kept per error. The tool does not apply source maps; for minified JavaScript use the Source Map Stack Trace Resolver.