Lodash _.toSafeInteger() Method

Beginner
5 min read
Updated: Nov 2026
5 examples
Lang
Decorative image with the word TOSAFEINTEGER

Definition

Converts value to a safe integer — an integer that can be compared and represented exactly in JavaScript numbers. Built on truncate-then-clamp to ±(253 − 1). Part of Lodash 4.x Lang.

Pass the value you want to inspect or convert. Read the return type carefully before you use the result.

Syntax

Call _.toSafeInteger. Start with this line.

Lodash
_.toSafeInteger(value)
CallWhat it does
_.toSafeInteger(value)Primary signature.

Prefer import toSafeInteger from "lodash/toSafeInteger" when you want a smaller bundle.

Library declarations
Lodash
_.toSafeInteger(value)

Parameters

ParameterDescription
valueRequired. Value to convert

Return Value

Return ValueDescription
*Integer in ±MAX_SAFE_INTEGER

Lodash Examples

Example 1 — Official Basics

Decimals, tiny values, Infinity, and numeric strings.

Lodash
_.toSafeInteger(3.2);
// → 3

_.toSafeInteger(Number.MIN_VALUE);
// → 0

_.toSafeInteger(Infinity);
// → 9007199254740991

_.toSafeInteger("3.2");
// → 3
Try It Yourself

How It Works

  1. 3.2. Truncates toward zero → 3.
  2. MIN_VALUE. Too small to keep as a non-zero integer → 0.
  3. Infinity. Clamped to MAX_SAFE_INTEGER.
  4. String. Parsed then truncated like the number case.

Example 2 — vs _.toInteger

Huge magnitudes stay huge with toInteger; safe clamps them.

Lodash
_.toInteger(1e20);
// → 100000000000000000000   // not safely exact

_.toSafeInteger(1e20);
// → 9007199254740991

_.toInteger(3.9);
// → 3

_.toSafeInteger(3.9);
// → 3
Try It Yourself

How It Works

  1. Same truncate. Both drop the fractional part toward zero.
  2. Huge value. toInteger keeps the unsafe magnitude.
  3. Clamp. toSafeInteger caps at MAX_SAFE_INTEGER.
  4. Small decimals. Results match when already in range.

Example 3 — ±Infinity Clamp

Infinities become the safe extremes.

Lodash
_.toSafeInteger(Infinity);
// → 9007199254740991

_.toSafeInteger(-Infinity);
// → -9007199254740991

Number.MAX_SAFE_INTEGER === 9007199254740991;
// → true
Try It Yourself

How It Works

  1. +∞. Clamped to the maximum safe integer.
  2. −∞. Clamped to the minimum safe integer.
  3. Never Infinity. Return type is always a finite integer.
  4. Constant. Matches Number.MAX_SAFE_INTEGER.

Example 4 — NaN and null

Invalid / empty-ish coercions settle at 0.

Lodash
_.toSafeInteger(NaN);
// → 0

_.toSafeInteger(null);
// → 0

_.toSafeInteger(undefined);
// → 0

_.toSafeInteger("abc");
// → 0
Try It Yourself

How It Works

  1. NaN path. Integer conversion treats NaN as 0.
  2. null. Coerces like +null → 0.
  3. undefined / junk. Become NaN then 0.
  4. Stable. You always get a finite integer back.

Example 5 — vs _.toLength

Different clamp windows for different jobs.

Lodash
_.toSafeInteger(-5);
// → -5

_.toLength(-5);
// → 0                    // lengths cannot be negative

_.toSafeInteger(1e20);
// → 9007199254740991

_.toLength(1e20);
// → 4294967295           // 2^32 − 1
Try It Yourself

How It Works

  1. Negatives. Safe integer keeps them; length forces 0.
  2. Huge positive. Both clamp — different ceilings.
  3. toLength. Cap is 232 − 1 (array length).
  4. Choose. IDs/counts → safe; array sizes → length.
Compatibility

Browser & Runtime Support

_.toSafeInteger is a Lodash 4.x Lang helper. It runs anywhere Lodash runs — modern browsers (CDN or bundle) and Node.js / Bun / Deno with npm install lodash. Native cousins: Number.isSafeInteger (check only) and manual clamp after Math.trunc.

✓ Stable · Lodash 4.x

_.toSafeInteger()

Available in [email protected] full builds and the lodash/toSafeInteger modular import. Works in evergreen browsers and current Node LTS when Lodash is installed.

100% With Lodash 4.x
Google Chrome Supported · Desktop & Mobile
Full support
Mozilla Firefox Supported · Desktop & Mobile
Full support
Apple Safari Supported · macOS & iOS
Full support
Microsoft Edge Supported · Chromium
Full support
Internet Explorer No native support · Use a polyfill
Polyfill
Opera Supported · Modern versions
Full support
Samsung Internet Supported · Android
Full support
Bun Supported · JavaScript runtime
Supported
Deno Supported · JavaScript runtime
Supported
Node.js Supported · Server runtime
Supported
Android WebView Supported · Modern WebView
Full support
_.toSafeInteger Lodash 4.x+

Bottom line: Safe for production once Lodash is loaded. Prefer import toSafeInteger from "lodash/toSafeInteger" for smaller builds. Use for IDs, counts, and values that must stay exactly representable.

Frequently Asked Questions

It converts value to an integer, then clamps it to ±Number.MAX_SAFE_INTEGER (±(2⁵³ − 1)) so the result can be represented exactly in IEEE-754 doubles.
Same truncate-toward-zero step, but toSafeInteger also clamps huge magnitudes. _.toInteger(1e20) stays huge; _.toSafeInteger(1e20) becomes 9007199254740991.
toLength clamps to [0, 2³² − 1] for array lengths. toSafeInteger allows negatives and a much larger upper bound.
Infinity → MAX_SAFE_INTEGER; −Infinity → −MAX_SAFE_INTEGER; NaN → 0.
No. It produces a safe integer. Use _.isSafeInteger (or Number.isSafeInteger) to test an existing number.
No. Conversion goes through number coercion and throws Cannot convert a BigInt value to a number.

Next: _.toString()

Convert values to strings with Lodash’s nullish and −0 rules.

_.toString() tutorial →

About the author

Mari Selvan M P
Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

  • Experience 12 years building web and cloud systems
  • Focus Full Stack Development, AWS, and Developer Education

I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

AWS Certified Developer – Associate (Credly)

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