IrfanView Batch Resize Alternatives

IrfanView has been around since 1996 and it is still, by a comfortable margin, the fastest image viewer on Windows. It opens a 40MB TIFF before Photoshop has finished drawing its splash screen. It’s free for personal use, the whole download is a few megabytes, and it will read essentially any image format that has ever existed.

Its batch resize is genuinely powerful. It’s also buried behind one of the most confusing dialogs in consumer software, which is why so many people search for how to use it and then search for something else.

Since you may well have landed here mid-task, let me tell you how to actually do it first. Then we can talk about whether you want to.

Doing It in IrfanView, Properly

Open IrfanView and press B, or go to File → Batch Conversion/Rename. This is the dialog that confuses everyone, so here’s the map.

At the top left, pick Batch conversion (not “Batch rename,” and not “Batch conversion - Rename result files” unless you want both).

The file browser occupies the middle. Navigate to your folder, select your images, and click Add — or Add all to take the lot. They appear in the list at the bottom. This trips people up constantly: selecting files in the browser does nothing until you click Add. The list at the bottom is the actual job.

Now the important part. Next to Output format, click Options to set JPEG quality if you’re outputting JPEG. Then tick Use advanced options (for bulk resize…) and click Advanced beside it. That’s where resize lives — not in the main dialog, which is why people hunt for it.

In the Advanced box, tick RESIZE, then choose your approach. Set new size takes explicit width and height in pixels. Set long/short side is usually what you actually want for mixed portrait and landscape images, since it resizes the longest edge to your number regardless of orientation. Tick Preserve aspect ratio, and tick Don’t enlarge smaller images unless you genuinely want upscaling — you almost never do, and leaving it off is how people end up with blurry enlarged thumbnails.

Set your output directory at the bottom, then click Start Batch. Point the output somewhere other than the source folder unless you want to overwrite your originals.

That’s it. Once you know where the resize option hides, it’s fast and it works on thousands of files without complaint.

So Why Look for Something Else?

Three reasons, and only one of them is about IrfanView being at fault.

You’re not on Windows. This is the big one. IrfanView is a Windows application. There’s no Mac build and no Linux build. You can run it under Wine or CrossOver with some fiddling, and people do, but “install a Windows compatibility layer to resize some photos” is a lot of yak-shaving for a ten-minute job.

The dialog defeats you. No shame in this. It’s a dense window with a file browser, two option panels, a nested Advanced dialog, and controls whose labels assume you already know the answer. Everything you need is there. Finding it the first time takes a while, and if you resize images twice a year you’ll re-learn it every time.

You can’t install software. Work-issued laptops with locked-down policies, shared machines, Chromebooks. IrfanView is a tiny install but it is an install.

If none of those apply to you — you’re on Windows, you’ve read the section above, you can install things — then honestly, stay with IrfanView. It’s free, it’s fast, and it will outperform every browser tool on very large batches. I’m not going to pretend otherwise to sell you something.

The Browser Option

If the blocker is platform or installation, running the resize in a browser sidesteps both.

BulkImagePro’s bulk resizer takes a folder of images, one target dimension, and resizes the batch. It runs on any OS with a modern browser, requires no install and no account, and processes locally via WebAssembly — files are read from your disk and never uploaded, which is the same privacy position as a desktop app rather than the usual web-tool trade.

Being straight about the comparison: IrfanView is faster on very large jobs. It’s native code with direct disk access; a browser tool works in memory with the overhead that implies. On a few thousand files, IrfanView wins clearly. On a few dozen or a few hundred, the difference is seconds and the setup time dominates.

IrfanView is also more configurable. Resample filters, sharpening after resize, colour depth, DPI, canvas operations, overlay text — the Advanced dialog exposes a lot, and a browser tool exposes a fraction of it deliberately. If you need specific control over the resampling algorithm, that’s a real reason to stay put.

What you get in exchange is that it works anywhere, immediately, with the resize option visible rather than nested two dialogs deep. And it chains straightforwardly into compression and format conversion on the same batch, which in IrfanView means configuring more of the same dialog. The bulk resizing guide covers choosing your target dimensions, which matters more than which tool applies them.

XnConvert: IrfanView’s Cross-Platform Cousin

If what you like about IrfanView is the power and the only problem is Windows, XnConvert is the closest thing to a direct port of the concept.

It’s free, it runs on Windows, Mac and Linux, and it’s built around the same idea: define a chain of operations and apply it to a folder. Resize, convert, rotate, watermark, rename — stack them, save the stack as a preset, reuse it. Format support is enormous, comparable to IrfanView’s.

The interface is arguably worse. It’s dense and unlovely in the same way, just differently arranged, so you’re trading one learning curve for another. But it’s a learning curve you can climb on a Mac, and the preset system is genuinely better than IrfanView’s for jobs you repeat.

Best for: people who want IrfanView’s capability but aren’t on Windows, and who’ll run the same batch job often enough to justify learning it.

ImageMagick: For the Terminal-Inclined

magick mogrify -resize 1600x1600 -path ./output *.jpg

That resizes every JPEG in a directory to fit within 1600×1600, preserving aspect ratio, writing to an output folder. It works identically on Windows, Mac and Linux.

For anyone who writes code, this is faster than any interface, scriptable, and has no limits beyond your hardware. mogrify overwrites in place if you omit -path, which has cost people their originals more than once — the -path ./output in that command is doing important safety work.

For anyone who doesn’t write code, learning a command line to resize photos is a disproportionate price. It’s the right answer for a specific audience and the wrong one for everybody else.

Photoshop, Briefly

If you already own Photoshop, its Image Processor (File → Scripts → Image Processor) does batch resize competently and you don’t need another tool. If you don’t own it, buying a subscription to resize images would be a strange decision, and the Photoshop batch resize alternatives comparison covers that ground properly.

Where I’d Land

On Windows, comfortable with the dialog, batches in the thousands. IrfanView. It’s free and it’s the fastest thing here. The instructions above cover the part people get stuck on.

On a Mac or Linux, want IrfanView-level power. XnConvert. Same philosophy, cross-platform, similar interface density.

Can’t install anything, or just want it done now. BulkImagePro. Works in any browser, nothing uploaded, resize option in plain sight.

You write code. ImageMagick, and you probably knew that.

Batches in the dozens, a few times a year. Any browser tool, honestly. The time you’d spend relearning IrfanView’s Advanced dialog exceeds the time the resize takes.

The one thing worth more attention than tool choice: what dimension you’re resizing to. A batch resized efficiently to the wrong size is still wrong. If the images are heading for social, the platform size reference lists what each network currently wants, and the aspect ratio calculator works out pixel dimensions for any ratio.

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Need a batch resized without installing anything? Try the BulkImagePro bulk resizer — drop in the folder, set one dimension, download the results. Runs in your browser on any OS, nothing uploaded, no signup. Need them compressed or converted to WebP afterwards? The compressor and format converter work on the same batch.

Frequently Asked Questions

How do I batch resize images in IrfanView?

Press B or choose File then Batch Conversion/Rename. Select "Batch conversion", navigate to your folder, select the images and click Add so they appear in the list at the bottom — selecting them in the browser alone does nothing. Tick "Use advanced options (for bulk resize...)" and click Advanced, then tick RESIZE and choose either a specific size or "Set long/short side" for mixed orientations. Enable "Preserve aspect ratio" and "Don't enlarge smaller images", set an output directory different from the source, then click Start Batch.

Is IrfanView available for Mac?

No. IrfanView is a Windows-only application with no native Mac or Linux build. It can be run through a compatibility layer such as Wine or CrossOver, but that adds significant setup for a simple task. For batch resizing on a Mac, XnConvert offers comparable capability natively across Windows, Mac and Linux, and browser-based tools such as BulkImagePro work on any operating system without installation.

Why can't I find the resize option in IrfanView's batch dialog?

Because it is not in the main batch dialog. You have to tick "Use advanced options (for bulk resize...)" and then click the Advanced button beside it, which opens a second window containing the RESIZE checkbox and its settings. This nesting is the single most common point of confusion with IrfanView's batch feature — everything you need is present, just one dialog deeper than most people expect.

Is IrfanView free?

IrfanView is free for personal and educational use. Commercial use requires a paid licence, which has historically been inexpensive — a one-off fee rather than a subscription. This is worth checking if you are using it for client work or inside a business, since the personal-use licence does not cover that.

What is the fastest way to batch resize images?

For very large batches — thousands of files — a native desktop application such as IrfanView or XnConvert, or ImageMagick from the command line, will be fastest, since they run as native code with direct disk access. For batches in the dozens or low hundreds, a browser-based tool finishes in seconds and the setup time matters more than raw throughput. In practice, the time spent configuring the tool usually exceeds the processing time unless the batch is genuinely large.

Does batch resizing reduce image quality?

Reducing dimensions discards pixel data by definition, but done correctly the result looks clean at its new size. The mistakes that actually cause visible damage are enlarging images beyond their original dimensions, which invents detail that was never there, and saving repeatedly to a lossy format so compression artifacts accumulate. Enable "don't enlarge smaller images" in any tool that offers it, and resize before compressing rather than after.