HAR File Compressor
Compress HTTP Archive (HAR) files online for free. Our HAR file compressor strips response bodies, cookies, and headers — then GZIP compresses the result for 80–95% size reduction. Analyzes your HAR file on upload to show exactly what's making it large. All processing happens in your browser. No signup required.
Upload a HAR (HTTP Archive) file to strip response bodies, cookies, and headers — then compress to GZIP for easy sharing. Shows per-entry analysis and estimated size reduction before processing. Your HAR file never leaves your device.
HAR files contain sensitive data — request URLs, headers, cookies, and response bodies. This tool processes everything locally in your browser. Your HAR file is never uploaded to any server.
Why Use Our HAR File Compressor?
Instant HAR File Compression
Compress HAR files instantly in your browser — no server upload, no cloud processing. Our har file compressor strips response bodies, cookies, and headers, then GZIP compresses the result for easy sharing.
Secure HAR File Compressor Online
HAR files contain sensitive data — request URLs, cookies, and response bodies. Our har file compressor processes everything locally in your browser. Your HAR file is never uploaded to any server.
HAR File Compressor — No Installation
Compress HAR files directly in your browser with no software downloads, no plugins, and no account required. Works on any modern browser on any operating system — no signup required.
HAR Analysis with Per-Entry Breakdown
The compressor analyzes your HAR file immediately on upload — showing total entries, response body size, header size, and cookie size. The top 5 largest response bodies are listed so you know exactly what's making your HAR file large.
Common Use Cases for HAR File Compressor
Sharing HAR Files with Support Teams
Compress HAR files before sharing with customer support or vendor support teams. A typical HAR file from a complex web app can be 50–200 MB — compressing to GZIP reduces it to 5–20 MB for easy email attachment or upload.
Bug Report Attachments
Compress HAR files before attaching to GitHub issues, Jira tickets, or Linear issues. The har file compressor strips response bodies (which contain sensitive data) while preserving the request/response structure needed for debugging.
Performance Analysis Archiving
Compress HAR files from WebPageTest, Lighthouse, and Chrome DevTools before archiving to S3 or GCS. HAR files compress extremely well with GZIP — typically 80–90% reduction — making long-term storage cost-effective.
Privacy-Safe HAR Sharing
Strip cookies and response bodies from HAR files before sharing with external parties. The har file compressor removes sensitive authentication tokens, session cookies, and API response data while preserving the network timing data.
API Testing & Mocking
Compress HAR files used as fixtures for API mocking tools (Mockoon, WireMock, Polly.js). Stripping response bodies and keeping only the request/response structure produces minimal HAR fixtures for test suites.
Team Collaboration & Code Review
Compress HAR files before sharing with teammates for code review and performance analysis. The har file compressor produces a clean, compact HAR that can be committed to version control or shared via Slack.
Understanding HAR File Compression
What is a HAR File?
A HAR (HTTP Archive) file is a JSON-formatted log of all HTTP requests and responses captured by a browser during a web session. HAR files are exported from Chrome DevTools, Firefox Developer Tools, Safari Web Inspector, and tools like WebPageTest and Lighthouse. They contain request URLs, headers, cookies, request bodies, response bodies, and timing data for every network request. HAR files are invaluable for performance analysis and debugging, but they can be very large — a complex web app session can produce a 50–200 MB HAR file. Our har file compressor strips the largest components and GZIP compresses the result, typically achieving 80–95% size reduction.
How Our HAR File Compressor Works
- 1Upload your HAR file: Drag and drop any
.haror.jsonfile. The HAR is parsed immediately and analyzed — showing total entries, response body size, header size, and the top 5 largest response bodies. Your file never leaves your device. - 2Choose stripping options: Select which components to remove — response bodies (recommended), cookies (recommended), request bodies, headers, and timing data. The estimated output size updates in real time based on your selections.
- 3Download the compressed file:Click "Compress HAR to GZIP" to download a
.har.gzfile, or disable GZIP to download a cleaned.harfile. The success message shows the exact size reduction achieved.
What Gets Stripped
- Response Bodies (recommended): The largest component of most HAR files — contains the full HTML, JSON, CSS, JS, and image data for every response. Stripping response bodies typically removes 70–90% of the HAR file size while preserving all timing and header data needed for performance analysis.
- Cookies (recommended): Session tokens, authentication cookies, and tracking cookies. Stripping cookies is recommended before sharing HAR files externally to prevent session hijacking.
- Request Bodies: POST data, form submissions, and API request payloads. Strip these when sharing HAR files that contain sensitive form data or API credentials.
- Headers: Request and response headers including Authorization, Cookie, Set-Cookie, and custom headers. Strip headers when sharing HAR files that contain API keys or authentication tokens in headers.
Important Limitations
The har file compressor uses the browser's native CompressionStream APIfor GZIP compression — supported by Chrome 80+, Firefox 113+, Safari 16.4+, and Edge 80+. The practical file size limit depends on your device's available RAM — most modern devices handle HAR files up to several hundred MB. For very large HAR files (over 500 MB), consider using command-line tools: jq 'del(.log.entries[].response.content.text)' file.har | gzip > file.har.gz.
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Frequently Asked Questions About HAR File Compressor
A HAR file compressor strips large components from HTTP Archive files (response bodies, cookies, headers) and compresses the result to GZIP — reducing file size by 80–95% for easy sharing. Our free har file compressor online works entirely in your browser — your HAR file is never uploaded to any server.
A HAR (HTTP Archive) file is a JSON log of all HTTP requests and responses captured during a browser session. HAR files are large because they contain the full response body for every request — HTML pages, JSON API responses, CSS files, JavaScript bundles, and even base64-encoded images. A complex web app session can produce a 50–200 MB HAR file.
HAR files contain sensitive data — session cookies, authentication tokens, and API response bodies. Always strip cookies and response bodies before sharing HAR files externally. The har file compressor's recommended options (strip response bodies + strip cookies) remove the most sensitive data while preserving the network timing data needed for performance analysis.
Absolutely. Our har file compressor processes everything locally in your browser. Your HAR file is never uploaded to any server, never stored, and never leaves your device. This is especially important given that HAR files contain sensitive authentication data.
Yes — 100% free, forever. No signup, no account, no premium tier, no file size limits, and no ads interrupting your workflow.
Stripping response bodies removes the actual content of HTTP responses (HTML, JSON, images) from the HAR file — this is a lossy operation that reduces file size by 70–90%. GZIP compression then compresses the remaining JSON structure — this is lossless and typically achieves an additional 80–90% reduction. Together, they can reduce a 100 MB HAR file to under 5 MB.
Decompress the .har.gz file first using `gunzip file.har.gz` on Linux/macOS, or 7-Zip on Windows. The resulting .har file can be opened in Chrome DevTools (Network tab → Import), Firefox Developer Tools, or HAR analysis tools like HAR Analyzer and Redbot.
Yes, but you need to decompress it first. Decompress the .har.gz file to get the .har file, then import it into Chrome DevTools via the Network tab → Import HAR. If you stripped response bodies, the response content will be empty but all request/response headers and timing data will be preserved.
Since processing runs entirely in your browser, the practical limit depends on your device's available RAM. Most modern devices handle HAR files up to several hundred MB without issues. For very large HAR files (over 500 MB), use the command line: `jq 'del(.log.entries[].response.content.text)' file.har | gzip > file.har.gz`.