LogExpert

A fast, LogExpert-inspired log analysis extension for VS Code — built as an independent personal developer tool to solve real log-viewing workflow needs.

Open any log file, filter it instantly, watch it live, chain filters across tabs, and bookmark positions — all without leaving the editor.

Opening LogExpert

Three ways to open LogExpert for any file:

1. Keyboard shortcut — Ctrl+Alt+F while the file is focused
2. Editor title bar — click the filter icon ($(filter)) in the top-right corner
3. Right-click — right-click any file tab or file in the Explorer → Open in LogExpert

.log files open directly in LogExpert with live follow enabled automatically.

Filter Panel + Auto Split View

Type a pattern and press Search (or Enter). Matching lines appear instantly, coloured by severity. A split view opens automatically — full file on top, filtered results below. Click any result to flash it in context. Double-click to open in the editor.

Close the results panel with ✕ when done.

Filter to Tab — Named Tabs

Click Filter to Tab to open the current filter results in a dedicated tab. The tab is named after the active filter — [ERROR] live.log, [WARN] live.log — so you always know what you're looking at.

Open multiple filtered tabs simultaneously, each streaming live independently.

Nested / Chained Filtering

This is the standout feature. From inside a filtered tab ([ERROR] live.log), run another search — the results are intersected with the primary filter. Click Filter to Tab again to lock that intersection into a new named tab: [ERROR+api-gateway] live.log.

The chain can go as deep as needed. Every tab inherits the full chain and applies it to live incoming lines.

Example workflow:

• Tab 1: [ERROR] live.log — all errors, live
• Tab 2: [ERROR+api-gateway] live.log — only api-gateway errors, live
• Tab 3: [ERROR+payment] live.log — only payment errors, live

All three update independently as the log file grows.

Live Follow Tail

Enable ⏬ Follow to stream new lines automatically as the file grows. All active chain filters are applied to incoming lines — only matching lines appear.

When you scroll up to investigate, a badge shows how many new matching lines have arrived. Click it to jump back to the bottom.

Filter History

Click the filter input to see your last 20 searches in a styled dropdown. Navigate with arrow keys, press Enter to select.

Right-click Context Menu

Right-click any result row:

Save Filtered Results

Right-click any row → Save filtered results… to export the current view to a .log or .txt file. The filename is pre-filled from the active filter pattern.

Column Parser (Columnizer)

Click Columns ▶ to parse structured log lines into separate columns. Choose a preset or let auto-detect pick the best one:

Two view modes

• Inline — columns replace the raw text in the main view, with a sticky header row
• Side-by-side — raw log on the left, parsed columns on the right, with synced scrolling and a draggable divider

Column visibility

Toggle individual columns on or off with checkboxes. Hidden columns disappear from both the view and saved output. For example, hide Timestamp to focus on just the service and message.

Save with columns

When columns are active, a "Save with columns" checkbox appears. When checked, saving filtered results exports only the visible columns (tab-separated with a header row) instead of the raw log lines. Uncheck it to save the original format.

If a preset doesn't match your data, the stats bar shows a warning: "Columns: 0/201 lines matched — try a different preset".

Line Highlighting

Lines are coloured automatically by the built-in rules:

Add custom rules via Highlights ▶ in the panel or Command Palette → Log: Add Highlight Rule. Rules are stored in VS Code settings and apply across all open log files.

Private (per-file) rules

Check "This file only" when adding a rule to keep it local to that panel. Private rules:

• Only highlight lines in the current panel — other open log files are unaffected
• Shown as a dashed-border chip with a "local" tag so you can tell them apart
• Are not saved to VS Code settings — they disappear when the panel is closed

Highlights only apply to files that have an active LogExpert panel open. Your .ts, .json, and other source files are never affected.

Bookmarks

Click Bookmarks ▶ to manage bookmarks for the current file.

Bookmarks persist across window reloads (stored per workspace).

Keybindings

All shortcuts are rebindable via File → Preferences → Keyboard Shortcuts.

Settings

Known Limitations

• Maximum 100 000 rows displayed at a time (a warning is shown when truncated).
• Split view is limited to files under 50 MB. Files over 10 MB show a performance warning.
• Back/fore context lines do not apply to live-arriving tail lines.

Contributing

Issues and pull requests welcome at the project repository.