---
title: "spring(_:blendDuration:)"
framework: swiftui
role: symbol
role_heading: Type Method
path: "swiftui/animation/spring(_:blendduration:)"
---

# spring(_:blendDuration:)

A persistent spring animation.

## Declaration

```swift
static func spring(_ spring: Spring, blendDuration: TimeInterval = 0.0) -> Animation
```

## Discussion

Discussion When mixed with other spring() or interactiveSpring() animations on the same property, each animation will be replaced by their successor, preserving velocity from one animation to the next. Optionally blends the duration values between springs over a time period.

## See Also

### Customizing spring animations

- [spring](swiftui/animation/spring.md)
- [spring(duration:bounce:blendDuration:)](swiftui/animation/spring(duration:bounce:blendduration:).md)
- [spring(response:dampingFraction:blendDuration:)](swiftui/animation/spring(response:dampingfraction:blendduration:).md)
- [interactiveSpring](swiftui/animation/interactivespring.md)
- [interactiveSpring(response:dampingFraction:blendDuration:)](swiftui/animation/interactivespring(response:dampingfraction:blendduration:).md)
- [interpolatingSpring](swiftui/animation/interpolatingspring.md)
- [interpolatingSpring(_:initialVelocity:)](swiftui/animation/interpolatingspring(_:initialvelocity:).md)
- [interpolatingSpring(duration:bounce:initialVelocity:)](swiftui/animation/interpolatingspring(duration:bounce:initialvelocity:).md)
- [interpolatingSpring(mass:stiffness:damping:initialVelocity:)](swiftui/animation/interpolatingspring(mass:stiffness:damping:initialvelocity:).md)