Excel as a Web Service

Turn Excel Into Live APIs.
Let AI Talk to Spreadsheets

Convert spreadsheets into secure, real-time web services. Give AI assistants, automation tools, and developers direct access — without hallucinations or broken logic.

SpreadAPI Product Dashboard

Why AI Struggles with Spreadsheet Math

We asked AI about its spreadsheet skills — here’s what it honestly told us.

"I Can't Run Your Formulas"

I see your formulas and Excel's results, but I can't execute them. I work with saved values, not live calculations.

- Claude, ChatGPT & Gemini

"I Only Know 50-100 Functions"

Basic math? Sure. But Excel has hundreds more - XIRR, YIELD, array formulas? I'll miss edge cases.

- Claude, being honest

"My Errors Compound Fast"

One small mistake in cell A1? By row 1000, I'm completely off. Error propagation is my nightmare.

- Every AI Model

"I Take Forever to Calculate"

1000+ formulas? That's 2-15 minutes of dependency mapping. Excel does it in 1-2 seconds.

- Every AI Model

"Complex Models? 20% Accuracy"

With 1000+ formulas, I have 20-40% chance of getting it right. SpreadAPI? Always 100%.

- Claude & ChatGPT

"I Can't Handle Dependencies"

Cell A depends on B, B on C... I spend most time figuring out order, not calculating.

- Gemini

Click here to see more AI limitations →

Here's How We Help AI Excel at Spreadsheet Math

Transform your spreadsheets into real-time APIs that AI can call — no guessing, no hallucinations, just accurate results powered by your Excel logic. Whether it’s simple calculations or complex chains of nested formulas, your Excel logic is executed exactly as you built it. The result: clean, reliable JSON that AI assistants, developers, and automation tools can work with — instantly and securely.

AI Sales Agents Creating Complex Excel Quotes

Your AI sales assistant can now generate accurate quotes using your actual Excel pricing models. No more approximations or hallucinations — just precise calculations from your trusted spreadsheets, accessible through a simple API.

100% Accurate Calculations

Your Business Logic Protected

Works with Any AI Assistant

I need a quote for 500 units with our enterprise discount, shipped to 3 locations in California
AI
I've calculated your quote using our Excel pricing model:
Base Price (500 × $47.99):$23,995.00
Enterprise Discount (15%):-$3,599.25
Volume Discount (500+):-$1,199.75
CA Shipping (3 locations):$485.00
CA Sales Tax (7.25%):$1,431.88
Total Quote:$21,112.88
Calculated by Excel in 47ms • 100% accurateDownload PDF
AI Excel Workflow Example

Automation Tools Running Your Excel Logic

Tools like Zapier, Make, and n8n can now trigger calculations in your Excel models with live inputs and return real results — instantly. No logic reimplementation. No formula rewrites. Just exact Excel behavior delivered as a secure, real-time API.

Plug & play with any workflow tool

Returns only clean JSON, never shows formulas

Handles any Excel complexity — IFs, XLOOKUPs, ARRAY functions, VAT logic, pricing

“Just convert this Excel to code”, they said.

It’s one of the most common dev requests — turning business-critical spreadsheets into code. But nested IFs, lookup chains, and constantly changing logic quickly turn it into a maintenance nightmare. With SpreadAPI, developers don’t need to rebuild spreadsheet logic — they can run it directly, through a secure and versioned API.

100% Formula Accuracy - VLOOKUP, SUMIFS, financial functions - they all work exactly as designed. Because it's real Excel, not a JavaScript approximation.
Business Users Keep Control - When formulas change, they update the Excel. Your API instantly reflects the changes. No code deployment needed.
Read: Why reimplementing Excel always fails →
Why Reverse Engineering Excel Fails - Don't re-code Excel, Just run Excel
Why We're Different

Give AI & Tools Excel Superpowers

Transform your spreadsheets into powerful APIs that can be called by applications, AI assistants, or integrated into any workflow. Your Excel expertise becomes instantly accessible.

Predictable Every Time

AI gives different answers each time. But Excel? Excel actually calculates. Every. Single. Time.

500+ Excel Functions

VLOOKUP, XLOOKUP, array formulas, financial functions - 500+ functions work exactly as in Excel

Real-Time Calculations

50ms response times with intelligent caching and pre-warmed Excel engines

No Files Sent to OpenAI/Anthropic

Your Excel stays on SpreadAPI servers. AI only sees the specific inputs and outputs you define

AI-Ready with MCP

Native Model Context Protocol support for seamless ChatGPT and Claude integration

Zero Learning Curve

Your team keeps using Excel as always. AI gets superpowers. No training needed

ABCDEF1234567AI Can EditQuantity500Discount15%AI Read-OnlyTotal$21,112Tax$1,432ProtectedAI can modify valuesAI can read onlyNo AI access

Editable Areas Give AI Controlled Access

Define exactly what parts of your spreadsheet AI can access. Grant read-only access to outputs, or let AI modify specific input cells or even formulas within designated areas. You stay in control while AI does the work.

Granular Permissions

Control exactly what AI can see and modify. Set permissions for values, formulas, formatting, and structure — keeping your core business logic secure.

Formula Intelligence

AI can not only read values but understand and even optimize your Excel formulas. Enable what-if scenarios and let AI experiment within safe boundaries.

Works With Every AI Platform and Automation Tool

SpreadAPI works with Claude, ChatGPT, and any AI assistant through our MCP server. Connect via REST API, webhooks, or integrate with Zapier, Make, and n8n. Your Excel calculations become accessible everywhere.

Start Building
Use Cases

What Game-Changing Technology Enables

Financial Advisors

Run complex what-if scenarios using actual Excel models. AI analyzes options without errors.

Business Analysts

Automate report generation from spreadsheet data. AI extracts insights from your calculations.

AI Assistants

Optimize spreadsheet formulas automatically. AI suggests improvements while preserving logic.

Sales Teams

Generate accurate quotes instantly. AI uses your pricing models to create perfect proposals.

Operations

Complex resource planning with Excel. AI optimizes allocation using your business rules.

Developers

Skip rebuilding Excel logic in code. Use spreadsheets as calculation engines via API.

Developer FAQ

Technical Questions Answered

Deep dive into the technical details. Built by developers, for developers.

How reliable are the calculations compared to native Excel?

SpreadAPI uses an advanced Excel-compatible calculation engine that supports all Excel features including array functions, dynamic arrays, and complex formulas. Every calculation is fully compatible with Excel, ensuring your formulas work exactly as expected. Our engine handles even the most sophisticated Excel features with 100% accuracy.

What happens to my proprietary formulas and business logic?

Your Excel formulas and business logic stay completely private. They're never exposed through the API or shared with AI providers. The API only returns calculation results, not the underlying formulas. Your intellectual property remains protected.

Is my data shared with AI providers like OpenAI or Anthropic?

No. Your Excel files stay on SpreadAPI's secure servers. AI assistants only access what you explicitly allow - specific cells or ranges you've granted permission to. They receive calculation results, not your full spreadsheet, keeping your proprietary formulas and sensitive data separate from AI training datasets.

Can SpreadAPI handle real-time data and streaming calculations?

Yes. SpreadAPI supports webhook triggers and real-time updates. When your Excel data changes, dependent calculations update automatically. You can also stream calculation results for live dashboards and monitoring systems.

What about Excel features like macros, pivot tables, and charts?

SpreadAPI supports most Excel features including pivot tables, data tables, and complex formulas. Charts and visualizations can be generated as data endpoints for your frontend to render. Note: VBA macros and linked workbooks are not currently supported.

How do you prevent calculation errors and handle edge cases?

SpreadAPI includes comprehensive error handling that mirrors Excel's behavior. #DIV/0!, #VALUE!, #REF! and other Excel errors are properly returned through the API. We also provide detailed error messages to help debug formula issues.

What's the latency for complex calculations?

Simple calculations return in 50-100ms. Complex models with thousands of formulas typically complete in 200-500ms. We use intelligent caching and pre-warming to minimize cold start times. For comparison, uploading a file to an LLM takes 5-10 seconds.

How does billing work for high-volume applications?

We offer transparent usage-based pricing with no hidden fees. Free tier includes 100 API calls/month. Paid plans start at $29/month for 10,000 calls. Enterprise customers get volume discounts and dedicated infrastructure.

Contact

Get Started in Minutes

Questions about SpreadAPI? We're here to help at team@airrange.io.