# Is there an image viewer for Windows that auto-refreshes the image when it is modified?

The single most important feature I am looking for is that the image viewer auto-refreshes the image (while you are viewing it) when it changes on the disk.

I have tried:

• Irfanview
• FastStone Image Viewer
• Windows Photo Viewer
• Imagine Picture Viewer
• pViewer
• Picasa

In case the version of Windows matters, it has to work on Windows 7. A free image viewer viewer is preferable. An open source one would be ideal.

It's been a while since I've used it (and I don't have a Windows box handy to test on) but I remember using an image viewer called JPEGView. From memory, I seem to recall it supporting the feature you need most: refreshing the display when the source file changes. In any event it is one of the few open-source image viewers for Windows that I found to holds its own.

It has a few extra tricks up its sleeve like the ability to slideshow a folder of images and do quick on the fly basic editing, but its real claim to fame is the lightweight interface that stays out of your way.

Another one is imgv but it seems to have been a long time since it was updated and I cannot find any evidence of whether it supports what you are looking for.

• JPEGView is perfect. +1 for it being an open source solution too and the fact that it refreshes faster than the FastStone image viewer. – Carl Jun 16 '14 at 21:13
• JPEGView is nice but it doesn't let you open more than two images! – Michael Jun 22 at 18:57

FastStone image viewer actually does work for this purpose. However, sometimes there can be a significant delay in the image refresh, which is what had me fooled when I posted the question.

None of the others do.

Neither JPEGView nor Okular worked for me, however FastStone Image Viewer worked.

Also Atom from Github is refreshing my image on file-change. Currently tested with png.

If you have access to Visual Studio you can easily write one.

Create a new F# Library project, right click on it and select Properties. Change the Output Type to Windows Application. Finally paste this code into Library.fs:

open System
open System.IO
open System.Windows.Forms

[<EntryPoint>]
let main argv =
match argv with
| [|filePath|] ->
if not <| File.Exists filePath then
printfn "File doesn't exist"
1
else
let path, file = Path.GetDirectoryName(filePath), Path.GetFileName(filePath)

use box =
new PictureBox(
ImageLocation = filePath,
SizeMode = PictureBoxSizeMode.Zoom,
Dock = DockStyle.Fill)

use form = new Form(Text = file)

use fsw = new FileSystemWatcher(path, file)
fsw.Changed.Add(fun _ -> box.ImageLocation <- filePath)
fsw.EnableRaisingEvents <- true

Application.Run(form)
0
| _ ->
Console.Error.WriteLine("Usage: ImageMonitor <filePath>")
2

• You should create an open source project on GitHub and take credit for this :) – Christian Rondeau Mar 17 '17 at 16:45

Sumatra PDF, though mainly used as a PDF reader, DJVU reader, and EPUB reader, can also open most image formats and automatically refreshes the document view, without locking the document if any other program is processing it. Quoting its web page, it opens:

PDF (.pdf) eBook formats: unencrypted EPUB (.epub) MOBI (.mobi)

Fiction Wise (.fb2, .fb2z, .zfb2) .pdb (Palm DOC format) .tcr

Comic book files: .cbz, .cbr, .cbt, .cb7z DjVu (.djv, .djvu)

Microsoft Compiled HTML Html (.chm) XPS (.xps)

Images (.tga, .gif, .jpg, .j2k,> .png, .webp, .tiff)

You can find further documentation at https://www.sumatrapdfreader.org/manual.html.

Okular is a document viewer that opens pdf, djvu, jpeg, png files, perhaps even more. It's a KDE app, since KDE is cross-platform, you may give it a try. Expect a big download though. On the other hand if you plan to use it on Linux, it should be pretty easy to get it up and running.

And yes, it auto refreshes when your file is changed on disk.

• yes, definitely. – qed Jun 16 '14 at 14:12
• Tried Okular, it didn't detect file change – A T Mar 16 '15 at 0:19
• I guess you tried it on Windows? – qed Mar 16 '15 at 0:20
• Yeah, Windows 7 with a remote network share. – A T Mar 16 '15 at 0:24
• See my answer - softwarerecs.stackexchange.com/a/17974/872 – A T Mar 18 '15 at 1:57

I just wrote a program, inspired by @Kit answer, with a few bonuses like retry, displaying last update time, etc. Very simple and straightforward, I hope it helps!

• I've tried it briefly and it worked well for me. Thanks for sharing! – Wizek Feb 3 '18 at 5:22

Visual Studio Code also refreshes the image on file change.

Windows Photo Viewer works just fine for me, but it's picky.

I have a script that outputs a PNG image. If I open the image in WPV from the explorer AND leave the explorer window open on that folder, then WPV updates in about half a second.

Otherwise, WPV doesn't seem to notice updates to the file.

This may be a bit unconventional but Sublime Text does this quite nicely. I haven't tested it with many file formats, but it's working for a PNG file just fine. In my particular case, I need it to update a python plot as I change it.

Leave it to a text editor to do what an image viewer should.