No Coding Required

Excel to API: Turn Any Spreadsheet Into a REST API

Your Excel spreadsheet already has the business logic. SpreadAPI turns it into a production-ready REST API — no developers needed, no formulas to rewrite, no accuracy to lose.

Convert Your Excel — Free See How It Works

The Problem: Excel Logic Trapped in Spreadsheets

Your team spent months building complex Excel models — pricing calculators, financial projections, engineering formulas. Now your app needs those calculations. The traditional options are painful:

Rewrite in Code

Weeks of developer time. Formulas get mistranslated. Business users can't update the logic without a code release.

Google Sheets API

Requires rebuilding in Google Sheets. 60 req/min rate limit. 2-5 second response times. Missing Excel-only features.

Microsoft Graph

Azure AD setup, complex OAuth, Office 365 subscription. Slow responses. Overkill for calculation APIs.

3 Steps, 5 Minutes

How to Convert Excel to API

Upload Your .xlsx File

Drag and drop your Excel file. SpreadAPI loads it into a server-side Excel engine that supports all formulas, VLOOKUP, INDEX/MATCH, pivot tables, and more. No conversion, no compatibility issues.

Define Inputs & Outputs

Select cells that accept parameters (e.g., loan_amount, interest_rate) and cells that return results (e.g., monthly_payment, total_interest). SpreadAPI auto-generates a typed API schema.

Publish & Call Your API

One click to publish. Your spreadsheet is now a live REST API. Call it from any language, any framework, any automation tool. Response time: 50-200ms.

Call Your API From Anywhere

Your Excel API works with any HTTP client. Here's a loan calculator example:

Request

curl -X GET \
  "https://spreadapi.io/api/v1
    /services/loan_calc/execute" \
  -d '{
    "loan_amount": 300000,
    "interest_rate": 0.045,
    "years": 30
  }'

Response (50-200ms)

{
  "outputs": {
    "monthly_payment": 1520.06,
    "total_interest": 247220.13,
    "total_paid": 547220.13
  },
  "metadata": {
    "executionTime": 12
  }
}

SpreadAPI vs. Alternatives

	SpreadAPI	Rewrite in Code	Google Sheets	MS Graph
Setup time	5 min	Weeks	Hours	Days
Uses your Excel file	Yes	No	No	Partially
Response time	50-200ms	Varies	2-5s	2-5s
Rate limits	Generous	Custom	60/min	10,000/day
Formula accuracy	100%	Risk of errors	~95%	100%
AI/MCP ready	Yes	Manual	No	No
Business users can update	Yes	No	Yes	Yes

Want a detailed comparison? See SpreadAPI vs Google Sheets API

Who Converts Excel to API?

Finance Teams

Pricing models, loan calculators, risk assessments. Keep the logic in Excel where analysts maintain it, expose results via API.

Developers

Skip weeks of formula rewriting. Get a REST API with typed inputs/outputs, OpenAPI spec, and batch execution support.

No-Code Builders

Connect Excel calculations to Zapier, Make, n8n, or Bubble. Add powerful business logic to any automation workflow.

Frequently Asked Questions

How do I convert an Excel spreadsheet to an API?

Upload your Excel file to SpreadAPI, define which cells are inputs and outputs, and click publish. Your spreadsheet is now available as a REST API endpoint that accepts JSON requests and returns calculated results.

Does SpreadAPI support all Excel formulas?

SpreadAPI supports most Excel formulas including VLOOKUP, INDEX/MATCH, SUMIFS, financial functions (PMT, IRR, NPV), statistical functions, and complex nested formulas. Pivot tables and charts are also supported.

How is this different from Google Sheets API?

Google Sheets API requires a Google account, has rate limits of 60 requests/minute, and requires you to rebuild your spreadsheets in Google Sheets format. SpreadAPI works with native Excel files, responds in 50-200ms, and supports complex Excel-only features like Power Query references.

Can I use my existing Excel files without modification?

Yes. Upload your .xlsx file as-is. SpreadAPI runs your formulas server-side using a full Excel-compatible engine. No need to rewrite formulas or restructure your spreadsheet.

What about Microsoft Graph Excel API?

Microsoft Graph requires an Office 365 subscription, Azure AD setup, and complex OAuth flows. Response times are typically 2-5 seconds. SpreadAPI is a simpler alternative: upload, define parameters, publish. No Microsoft account needed, 50-200ms response times.

Is there a free tier?

Yes. The free tier includes 1 service (spreadsheet API) with up to 1,000 API calls per month. No credit card required to get started.

Your Excel Already Works. Make It an API.

Upload your spreadsheet, define inputs and outputs, publish. Takes 5 minutes.

Get Started Free