Log Viewer & Filter

About this tool

Paste logs and filter them by a keyword or log level so you can focus on the lines that matter.

Example

Input: filter "ERROR"

Output: only lines containing ERROR

Privacy

This tool runs entirely in your browser. Your data is processed locally and never uploaded to a server.

How to use this tool

1. Paste your log text into the input box.
2. Choose a log level like ERROR, WARN, or INFO, or type a keyword to search for.
3. Run the filter to keep only matching lines.
4. Review the remaining lines and adjust the keyword or level if needed.

Step by step, what happens

1. The tool reads the pasted text line by line and treats each line as a separate log entry.
2. It checks each line against the selected log level or keyword filter.
3. Only lines that match are shown in the output, which makes noisy logs easier to scan.
4. If you change the filter, the viewer updates so you can narrow down the relevant events quickly.

Worked example

Here is a small app log where you only want to see error messages.

Input: INFO Server started WARN Disk space is low ERROR Failed to connect to database INFO Retrying connection

1. Paste the four log lines into the log viewer.
2. Set the filter to ERROR so only error lines are kept.
3. The tool scans each line and hides the INFO and WARN entries.

Tips and common mistakes

• Use a log level filter when your logs already include labels like ERROR, WARN, or INFO.
• Use a keyword filter for values that are not log levels, such as a user id, request id, or service name.
• Make sure each log entry is on its own line, or the viewer may not filter it the way you expect.
• If nothing appears, check that the filter text matches the log text exactly enough to find it.

Frequently asked questions