Isn't there an easy way to pinch to zoom in an image in Swiftui?

The SwiftUI API is pretty unhelpful here: the onChanged gives number relative to start of current zoom gesture and no obvious way within a callback to get the initial value. And there is an onEnded callback but easy to miss/forget.

A work around, add:

@State var lastScaleValue: CGFloat = 1.0

Then in the callback:

.gesture(MagnificationGesture().onChanged { val in
            let delta = val / self.lastScaleValue
            self.lastScaleValue = val
            let newScale = self.scale * delta

//... anything else e.g. clamping the newScale
}.onEnded { val in
  // without this the next gesture will be broken
  self.lastScaleValue = 1.0

where newScale is your own tracking of scale (perhaps state or a binding). If you set your scale directly it will get messed up as on each tick the amount will be relative to previous amount.

Here's one way of adding pinch zooming to a SwiftUI view. It overlays a UIView with a UIPinchGestureRecognizer in a UIViewRepresentable, and forwards the relevant values back to SwiftUI with bindings.

You can add the behaviour like this:


This adds behaviour similar to zooming photos in the Instagram feed. Here's the full code:

import UIKit
import SwiftUI

class PinchZoomView: UIView {

    weak var delegate: PinchZoomViewDelgate?

    private(set) var scale: CGFloat = 0 {
        didSet {
            delegate?.pinchZoomView(self, didChangeScale: scale)

    private(set) var anchor: UnitPoint = .center {
        didSet {
            delegate?.pinchZoomView(self, didChangeAnchor: anchor)

    private(set) var offset: CGSize = .zero {
        didSet {
            delegate?.pinchZoomView(self, didChangeOffset: offset)

    private(set) var isPinching: Bool = false {
        didSet {
            delegate?.pinchZoomView(self, didChangePinching: isPinching)

    private var startLocation: CGPoint = .zero
    private var location: CGPoint = .zero
    private var numberOfTouches: Int = 0

    init() {
        super.init(frame: .zero)

        let pinchGesture = UIPinchGestureRecognizer(target: self, action: #selector(pinch(gesture:)))
        pinchGesture.cancelsTouchesInView = false

    required init?(coder: NSCoder) {

    @objc private func pinch(gesture: UIPinchGestureRecognizer) {

        switch gesture.state {
        case .began:
            isPinching = true
            startLocation = gesture.location(in: self)
            anchor = UnitPoint(x: startLocation.x / bounds.width, y: startLocation.y / bounds.height)
            numberOfTouches = gesture.numberOfTouches

        case .changed:
            if gesture.numberOfTouches != numberOfTouches {
                // If the number of fingers being used changes, the start location needs to be adjusted to avoid jumping.
                let newLocation = gesture.location(in: self)
                let jumpDifference = CGSize(width: newLocation.x - location.x, height: newLocation.y - location.y)
                startLocation = CGPoint(x: startLocation.x + jumpDifference.width, y: startLocation.y + jumpDifference.height)

                numberOfTouches = gesture.numberOfTouches

            scale = gesture.scale

            location = gesture.location(in: self)
            offset = CGSize(width: location.x - startLocation.x, height: location.y - startLocation.y)

        case .ended, .cancelled, .failed:
            isPinching = false
            scale = 1.0
            anchor = .center
            offset = .zero


protocol PinchZoomViewDelgate: AnyObject {
    func pinchZoomView(_ pinchZoomView: PinchZoomView, didChangePinching isPinching: Bool)
    func pinchZoomView(_ pinchZoomView: PinchZoomView, didChangeScale scale: CGFloat)
    func pinchZoomView(_ pinchZoomView: PinchZoomView, didChangeAnchor anchor: UnitPoint)
    func pinchZoomView(_ pinchZoomView: PinchZoomView, didChangeOffset offset: CGSize)

struct PinchZoom: UIViewRepresentable {

    @Binding var scale: CGFloat
    @Binding var anchor: UnitPoint
    @Binding var offset: CGSize
    @Binding var isPinching: Bool

    func makeCoordinator() -> Coordinator {

    func makeUIView(context: Context) -> PinchZoomView {
        let pinchZoomView = PinchZoomView()
        pinchZoomView.delegate = context.coordinator
        return pinchZoomView

    func updateUIView(_ pageControl: PinchZoomView, context: Context) { }

    class Coordinator: NSObject, PinchZoomViewDelgate {
        var pinchZoom: PinchZoom

        init(_ pinchZoom: PinchZoom) {
            self.pinchZoom = pinchZoom

        func pinchZoomView(_ pinchZoomView: PinchZoomView, didChangePinching isPinching: Bool) {
            pinchZoom.isPinching = isPinching

        func pinchZoomView(_ pinchZoomView: PinchZoomView, didChangeScale scale: CGFloat) {
            pinchZoom.scale = scale

        func pinchZoomView(_ pinchZoomView: PinchZoomView, didChangeAnchor anchor: UnitPoint) {
            pinchZoom.anchor = anchor

        func pinchZoomView(_ pinchZoomView: PinchZoomView, didChangeOffset offset: CGSize) {
            pinchZoom.offset = offset

struct PinchToZoom: ViewModifier {
    @State var scale: CGFloat = 1.0
    @State var anchor: UnitPoint = .center
    @State var offset: CGSize = .zero
    @State var isPinching: Bool = false

    func body(content: Content) -> some View {
            .scaleEffect(scale, anchor: anchor)
            .animation(isPinching ? .none : .spring())
            .overlay(PinchZoom(scale: $scale, anchor: $anchor, offset: $offset, isPinching: $isPinching))

extension View {
    func pinchToZoom() -> some View {

The other answers here are overly complicated with custom zooming logic. If you want the standard, battle-tested UIScrollView zooming behavior you can just use a UIScrollView!

SwiftUI allows you to put any UIView inside an otherwise SwiftUI view hierarchy using UIViewRepresentable or UIViewControllerRepresentable. Then to put more SwiftUI content inside that view, you can use UIHostingController. Read more about SwiftUI–UIKit interop in Interfacing with UIKit and the API docs.

You can find a more complete example where I'm using this in a real app at: (That example also includes more tricks for centering the image.)

var body: some View {
  ZoomableScrollView {
    Image("Your image here")

struct ZoomableScrollView<Content: View>: UIViewRepresentable {
  private var content: Content

  init(@ViewBuilder content: () -> Content) {
    self.content = content()

  func makeUIView(context: Context) -> UIScrollView {
    // set up the UIScrollView
    let scrollView = UIScrollView()
    scrollView.delegate = context.coordinator  // for viewForZooming(in:)
    scrollView.maximumZoomScale = 20
    scrollView.minimumZoomScale = 1
    scrollView.bouncesZoom = true

    // create a UIHostingController to hold our SwiftUI content
    let hostedView = context.coordinator.hostingController.view!
    hostedView.translatesAutoresizingMaskIntoConstraints = true
    hostedView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
    hostedView.frame = scrollView.bounds

    return scrollView

  func makeCoordinator() -> Coordinator {
    return Coordinator(hostingController: UIHostingController(rootView: self.content))

  func updateUIView(_ uiView: UIScrollView, context: Context) {
    // update the hosting controller's SwiftUI content
    context.coordinator.hostingController.rootView = self.content
    assert(context.coordinator.hostingController.view.superview == uiView)

  // MARK: - Coordinator

  class Coordinator: NSObject, UIScrollViewDelegate {
    var hostingController: UIHostingController<Content>

    init(hostingController: UIHostingController<Content>) {
      self.hostingController = hostingController

    func viewForZooming(in scrollView: UIScrollView) -> UIView? {
      return hostingController.view