Har Assist

A visual HAR assistant for VS Code with automatic file opening, fast request filtering, resizable tables, and split request/response inspection.

Independent project: Har Assist is independently maintained by ceendev and published by yeceen. It is based on the GPL-licensed HAR Analyzer by Matt Foulks and is not affiliated with, endorsed by, or published by Matt Foulks.

Open a .har file and Har Assist takes over automatically. The file opens as a dedicated read-only network workspace instead of raw JSON, including large HAR files that exceed VS Code's normal text-document size limit.

Highlights

• Open .har files directly with a first-class VS Code custom editor.
• Filter by domain, application, protocol, method, content type, status, or text.
• Horizontally scroll complete request URLs in a resizable request table, with duration and status pinned to the right and the header fixed vertically.
• Keep the selected request URL in the top Inspector bar and drag horizontally to reveal long paths and query strings; hover the bar to reveal its copy button, with pointer-local success feedback.
• Open request and response details in a draggable split inspector.
• Inspect a Reqable-style overview with basic metadata and collapsible application, connection, timing and size groups. Preserve Reqable's microsecond timestamps, align resizable key/value columns, and distinguish unknown values from zero.
• Resize columns throughout the request list and inspector tables.
• Collapse either the request or response inspector while keeping one visible.
• View JSON, XML, HTML, JavaScript, CSS and plain text in read-only CodeMirror controls; JSON is automatically indented without changing number tokens or keys.
• Inspect the complete HTTP message in both Raw tabs, with exactly 文本 and Hex modes. Both include the start line, all headers, separator and body. Hex serializes the HAR header fields and appends decoded Base64 body bytes unchanged (or UTF-8 text when only text was saved).
• Switch request and response bodies to Hex with byte offsets, ASCII, byte search and selection/copy, including JSON, text, XML and HTML in standalone tabs. Hex uses decoded Base64 bytes directly, or the unchanged HAR text as UTF-8; JSON formatting and HTML preview never alter its content.
• Preview images with zoom/pan/rotate, and play captured audio/video when the content is complete and its codec is supported by VS Code.
• HTML Preview first shows a risk notice and a 确认预览 button. Only clicking this button enables captured scripts, live resources, links and forms; other requests and new tabs require their own confirmation. Relative resources resolve against the recorded request URL. The preview stays isolated from the VS Code host, and browser/site security policies still apply. HAR/source bytes stay unchanged.
• Double-click the fixed open-tab hint to use the same viewer in a separate tab.
• Parse HAR data directly in the WebView, with available memory as the practical file-size limit.

Filters within a quick-filter group use OR; different groups, domain, application, and search filters use AND. All clears only the quick filters, while the search clear button clears only the search text. Search is case-insensitive and covers the complete captured request/response headers and bodies, not just the body preview. Starts with and Equals match individual values in the selected scope (for example a URL, header value, or body).

Development

Use Node.js 22 or later:

npm ci
npm run check
npm run package
npm run check:package

The package command creates har-assist.vsix. Install it with VS Code's Extensions: Install from VSIX... command.

GitHub Actions builds pushes and pull requests targeting ceen or main. Pushing a new package version automatically creates its tag/Release and publishes to Marketplace after source and VSIX tests succeed. See Publishing.

License and attribution

Har Assist is released under GPL-3.0 and retains the original project's license and copyright notices. The current extension has a new identity, original icon, automatic custom-editor integration, large-file loading, a redesigned filtering toolbar, a split request/response inspector, and resizable tables.

The Har Assist icon was created specifically for this project without using the upstream artwork as an input or reference. See Artwork provenance.