When APIs don't exist and headless crawlers get blocked: Custom Browser Extensions.
Enterprise sites and government portals deploy sophisticated Cloudflare bot checks, CAPTCHAs, and session expirations that break traditional scrapers. I build lightweight, secure in-browser extensions that run inside your normal authenticated browser session—extracting structured data, parsing documents client-side, and streaming clean records straight into your database with one click.
Why In-Browser Human-in-the-Loop Beats Brittle Headless Bots
- • Cloudflare & Bot-Block Vulnerability: Frequent HTTP 403s, browser fingerprint bans, and rotating CAPTCHA traps.
- • Expensive Proxy Infrastructure: Burning $500+/mo on residential proxies just to scrape a few hundred pages.
- • High Breakage & Upkeep: A single CSS class tweak on the target site breaks headless Puppeteer scripts overnight.
- • Runs in Your Genuine Browser Session: You pass 2FA or bot verification naturally as a human visitor; the extension extracts the rendered DOM.
- • Client-Side Document Parsing: Uses bundled PDF.js or WASM parser right in the tab—zero external server bandwidth or scraping footprint.
- • One-Click Secure Ingestion: Preview parsed records before clicking "Send to Cloud", preventing corrupted database states.
Two Production Extensions Built for Demanding Workflows
UPC Intel Court Capture
The Unified Patent Court portal houses critical European patent dispute decisions, but sits behind aggressive bot shields and offers no public API. This extension allows legal analysts to browse court decisions normally and capture entire docket batches with a single click.
UPC_CFI_196/2025 vs UPC-CFI-0000029/2026), extracts claimant/defendant names, dates, and court divisions without missing rows.
Retry-After headers to protect user IP reputation.
LinkedIn & Sales Nav Sidepanel Runner
Heavy $150/month sales automation tools flood accounts with robotic actions that trigger automated security restrictions. This Chrome Sidepanel extension runs right alongside LinkedIn Sales Navigator, managing hyper-personalized outreach campaigns with human-like behavioral pauses.
Inside a Boxfixe Browser Extension
Click the interactive tabs below to see how the four layers of a modern Manifest V3 extension interact securely with your existing backend.
What Kind of Browser Extension Does Your Team Need?
If your analysts, associates, or operators are wasting hours manually copying data between browser windows, a custom extension can compress that work into seconds.
Registry & Auction Scrapers
Extract commercial real estate listings, insolvency auction records, or corporate filings directly from regional gazettes and European registries while you browse.
CRM Enrichers & Quick-Clips
Clip LinkedIn, Crunchbase, or conference directory contacts into your custom CRM table with automated email pattern resolution and duplicate detection.
Instant Sanction & Court Flags
Overlay risk badges directly on vendor or counterparty websites by querying your internal risk database in real time through an extension sidepanel.
Have a workflow you want automated inside Chrome?
Send me a 2-minute Loom video or description of what your team does manually in the browser. I'll scope the extension, provide a fixed quote, and deliver working source code ready for unpacked developer mode or private Web Store installation.