TS2769: No overload matches this call

What’s happening?

This error occurs when you call a function with arguments that don’t match any of its overload signatures.

Overloaded functions accept multiple argument patterns, and TypeScript checks that your call matches at least one.

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Reproduction

function format(value: string): string;
function format(value: number, decimals: number): string;
function format(value: string | number, decimals?: number): string {
  if (typeof value === "number") {
    return value.toFixed(decimals);
  }
  return value;
}

format("Hello"); // ✅ Matches first overload
format(3.14159, 2); // ✅ Matches second overload
format(3.14159); // ❌ No overload matches this call

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Why does TypeScript complain?

TypeScript checks the overload signatures (not the implementation):

• format(string) → ✅
• format(number, number) → ✅
• format(number) → ❌ No matching overload

The implementation signature is only for internal use.

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Solutions

Option 1: Add a matching overload

function format(value: string): string;
function format(value: number): string; // ✅ Add this overload
function format(value: number, decimals: number): string;
function format(value: string | number, decimals?: number): string {
  if (typeof value === "number") {
    return value.toFixed(decimals ?? 2); // Default decimals
  }
  return value;
}

format(3.14159); // ✅ Now matches second overload

When to use:

• ✅ When the call pattern is valid and should be supported

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Option 2: Provide all required arguments

format(3.14159, 2); // ✅ Matches existing overload

When to use:

• ✅ When you can provide the missing arguments
• ✅ Simplest fix if arguments are available

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Option 3: Use a type assertion (if you’re certain)

(format as (value: number) => string)(3.14159); // ⚠️

When to use:

• ⚠️ Only when you know the implementation supports it
• ⚠️ Not recommended - fix the overloads instead

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Common scenarios

React.createElement overloads

React.createElement("div", { className: "container" }); // ✅
React.createElement("div", "Hello"); // ❌ No overload matches
// Second argument must be props object or null

// ✅ Fix:
React.createElement("div", null, "Hello");

Array.from with mapping

Array.from([1, 2, 3], x => x * 2); // ✅
Array.from([1, 2, 3], x => x * 2, thisArg); // ❌ No overload matches
// Array.from doesn't accept a third argument in this way

// ✅ Fix: Use map instead
[1, 2, 3].map(x => x * 2);

fetch API

fetch("/api/data", { method: "POST" }); // ✅
fetch("/api/data", { method: "POST", body: { data: "value" } });
// ❌ No overload matches
// body must be a string or FormData, not an object

// ✅ Fix:
fetch("/api/data", {
  method: "POST",
  body: JSON.stringify({ data: "value" })
});

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Key takeaways

• Overload signatures define the allowed call patterns
• The implementation signature is not checked by callers
• Add missing overloads for valid call patterns
• Check library documentation for correct argument types

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Additional resources

• Function Overloads