Best Free Image Resizers in 2026: Reviewed and Compared

Need to resize an image quickly? In 2026, there are dozens of free tools — browser-based, desktop software, and command-line — each with different tradeoffs for speed, quality, batch support, and privacy. This review covers the best free image resizers available right now.

What to Look for in an Image Resizer

Before diving into tools, here are the key criteria that matter:

• Speed: How fast does it process a batch of 20+ images?
• Quality: Does the resized image look sharp, or does it look soft/artifacted?
• Formats supported: JPG, PNG, WebP, AVIF, HEIC, GIF support?
• Batch processing: Can you resize multiple files at once?
• Privacy: Does it process files locally, or upload to a server?
• Output control: Can you set exact pixel dimensions or percentage?

1. Picovert (Browser, Free)

Picovert's Image Resizer runs entirely in the browser using WebAssembly and sharp under the hood. Files never leave your device, which is a major privacy advantage. It supports JPG, PNG, WebP, AVIF, HEIC, BMP, and GIF. Batch processing allows resizing dozens of files at once. The output quality is excellent — Picovert uses Lanczos resampling for sharp downscaling. No account or installation required.

2. Squoosh (Browser, Free)

Squoosh by Google is a powerful image compression and conversion tool that includes basic resizing. It processes files locally in the browser and supports a wide range of formats including AVIF and JpegXL. The tradeoff is that Squoosh handles one file at a time — no batch processing. Best for power users who want fine-grained control over every setting.

3. GIMP (Desktop, Free/Open Source)

GIMP is the gold standard free desktop image editor. The Image → Scale Image menu provides full control over width, height, and interpolation type. GIMP supports all major formats and is great for resizing with custom aspect ratios. The downside is the steep learning curve for new users and no batch resize without scripting.

4. IrfanView (Windows, Free)

IrfanView is a lightweight Windows image viewer with excellent batch processing via Batch Conversion. You can resize hundreds of images at once, apply format conversions, and add watermarks. It's fast, free, and supports virtually every format. Mac users need a different option.

5. Preview (macOS, Built-in)

macOS Preview has a hidden Tools → Adjust Size feature that resizes images directly. It handles JPG, PNG, HEIC, and TIFF well. Preview does not support batch resizing unless you select multiple files in Finder first, which is limited. For casual Mac users who need to resize one or two images, Preview is the easiest option.

Comparison Table

Here is a quick overview of how these tools compare:

• Picovert: Browser, private, batch, all formats, sharp quality — Best overall
• Squoosh: Browser, private, single file, great control — Best single-file
• GIMP: Desktop, free, advanced editing — Best for power users
• IrfanView: Windows only, batch, fast — Best for Windows batch
• Preview: macOS built-in, simple — Best for occasional Mac use

Recommendation for Most Users

For most users who need fast, private, batch image resizing with no software to install, Picovert is the best free image resizer in 2026. Start with the free Image Resizer — it handles the most common resizing tasks in seconds, and you can combine it with the Image Compressor for optimized output.

No single tool is perfect for every workflow. For heavy batch work on Windows, IrfanView is hard to beat. For individual files with maximum quality control, Squoosh is excellent. For most everyday needs, a browser-based tool like Picovert is the fastest and most privacy-friendly choice.