Interest Rate Comparison Overlay

WHAT IT DOES

This script automatically scans any page for interest rates, APRs, and loan terms, then compares them to a user-configured benchmark rate. A floating overlay or badge shows at a glance whether each detected rate is above, below, or near the benchmark, with color-coded visual indicators (red for above, green for below, yellow for near) and percentage difference. The overlay displays the benchmark rate, a list of detected rates with their status and difference, and the total number of rates found. Perfect for comparing loan offers, credit card APRs, mortgage rates, and investment returns against a baseline.

WHERE IT RUNS

The script works on any page with interest rate information—banking websites, loan comparison sites, credit card applications, mortgage calculators, investment platforms, financial news, and any page displaying percentages. It detects rates using pattern matching for percentage signs and rate-related keywords (APR, interest, rate, loan, mortgage, credit card) and works on any website regardless of framework.

HOW TO USE

After installation, the script automatically scans the page for interest rates. A floating badge shows the first detected rate and how it compares to the benchmark. Click the badge to toggle the full overlay with all detected rates. Open the panel to customize: set the benchmark rate (0-30%), choose benchmark type (Prime Rate, Federal Funds, Average, Custom), enable or disable the overlay and badge, choose overlay position (top-right, top-left, bottom-right, bottom-left), adjust opacity, select dark or light theme, customize colors for above, below, and near rates, and choose badge position. Click "Scan Now" to manually re-scan the page.

TECHNICAL MECHANISM

The script uses a multi-stage rate detection pipeline. First, it scans the DOM for elements likely to contain rates using a comprehensive set of selectors (.rate, .apr, .interest, .percentage, .finance, .loan, .card, .mortgage) with fallback to text-based detection across common content containers. Second, it extracts rate values using multiple regex patterns that capture percentages in various formats (e.g., "5.5%", "Rate: 6.75%", "APR 4.99"). Third, it validates extracted rates to ensure they are within realistic ranges (0-100) and deduplicates by label and value. Fourth, it compares each rate to the user-configured benchmark (default 7.0%) with a configurable tolerance threshold (0.5%) to determine status: above, below, or near. Fifth, it renders the overlay with color-coded indicators and percentage difference. Sixth, it displays a badge showing the status of the first detected rate.

THE PANEL

The settings panel is fully draggable and can be positioned anywhere on your screen. It automatically snaps to the nearest edge when released, keeping your workspace organized. The panel can be collapsed to a small bubble showing only a gear icon, and restored with a single click. Its position is remembered across page reloads using GM_setValue. The panel also responds to the Escape key, which instantly hides it until you click the bubble again. All settings are saved immediately when changed and persist across browser sessions.

PLEASE NOTE

This script requires the free BotGentz extension to run. Rate detection relies on text pattern matching and may not capture all formats or miss rates in complex layouts. The script does not access, store, or transmit any personal data, financial information, or browsing history. All processing happens locally in your browser and never leaves your device.