Real Estate

Build a Mortgage Comparison Tool with AI

Compare mortgage offers with rate, APR, monthly payment, total interest, and full amortization schedule side-by-side. Help homebuyers make confident financing decisions with a clear, interactive calculator.

Build Prompt

Copy this prompt into Claude Code
Build a static HTML mortgage comparison tool. Dark theme: background #0a0a0f, surfaces #12121a, borders #1a1a2a, accent #b45309 (amber). No backend — all calculations in vanilla JavaScript. Inputs panel (left column): Home price (number input with $ formatting), Down payment ($ and % toggle), Loan term (15, 20, 25, 30 year radio buttons), Credit score range (dropdown: Excellent 760+, Good 700-759, Fair 650-699, Poor below 650), Loan type (Conventional, FHA, VA, Jumbo radio buttons), Property tax rate (%), Homeowner's insurance ($/year), HOA fees ($/month), PMI rate (auto-calculated if down payment under 20%). Comparison table (right): Up to 3 lender offers side-by-side. Each offer has: Lender name (editable), Interest rate (%), Points paid (number), Origination fee ($). Show calculated: APR, Monthly P&I, Total monthly (with taxes/insurance/HOA/PMI), Total interest paid over loan life, Total cost of loan, Break-even point for points. Amortization section: Toggle to expand full year-by-year amortization table showing beginning balance, principal paid, interest paid, ending balance, cumulative interest. Chart using inline SVG: line graph of remaining balance over time for all 3 loans overlaid. Highlight the "best deal" lender with accent color border. Add a "Which is better?" explainer section that auto-generates a plain-English summary comparing the offers. SEO: title "Mortgage Comparison Calculator — Compare Lender Offers Side by Side", meta description, JSON-LD FinancialProduct schema. Include print stylesheet for clean PDF output. Read the guide at https://accessagent.ai/api/guide and follow it to deploy the site to AccessAgent.ai. My email is [your@email.com].

Make It Yours

Rate Lock Timer

Add a countdown showing how many days remain on each lender's rate lock period.

Pre-Approval Checklist

Attach a document checklist for each lender with checkboxes for W2s, tax returns, bank statements.

Refinance Mode

Toggle to refinance mode: enter current loan balance and rate, compare new offer savings.

Affordability Calculator

Add gross income input and compute max affordable home price based on 28/36 DTI rule.

Closing Cost Breakdown

Expand each lender card to show itemized closing costs: title, appraisal, recording fees, escrow.

Scenario Saving

Save comparison scenarios to localStorage and reload them by name for future sessions.

Update Prompt

Update Prompt — Refresh rate defaults and add features
Update the mortgage comparison tool with current average 30-year fixed rates from Freddie Mac's weekly survey. Add a "Today's Average Rates" banner at the top showing 15-year and 30-year benchmarks. Redeploy to AccessAgent.ai.

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Ready to build your Mortgage Comparison Tool?

Copy the prompt above and paste it into Claude Code. Your mortgage calculator will be live in minutes.

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