ARW vs ICO — Differences, File Size & When to Use Each

Q: What is an ARW file?

ARW (Sony RAW ARW) is an image format used to store raster graphics — a two-dimensional grid of pixels describing a picture. It is part of the raster &amp; vector images family and designed around a specific trade-off between file size, visual fidelity, and feature support (transparency, colour depth, compression type). Photographers, web designers, and content creators choose ARW when its particular strengths match the publishing target.

Q: How do I open an ARW file?

Most desktop photo viewers (Windows Photos, macOS Preview, GIMP, Photoshop, Affinity Photo) open ARW natively. On mobile, iOS Photos and Google Photos display ARW in the gallery when supported by the OS. If the format is rare or new, convert to JPG or PNG first — both are universally readable — using our ARW to JPG or ARW to PNG converter.

Q: How do I convert an ARW file to another format?

Upload the ARW to KaijuConverter and pick a target format (JPG, PNG, WebP, HEIC, TIFF, BMP, SVG, PDF). The conversion runs in the browser via ImageMagick and returns a download in seconds. No account or installation required; both input and output delete automatically within two hours.

Q: Is ARW better than JPG or PNG?

It depends on the task. JPG is the smallest file size for photographs; PNG is lossless with transparency; ARW has its own niche that may favour colour depth, animation, or encoding efficiency over one or both of those. For the final web publish, test all three and measure file size plus visible quality on real content.

Q: What is an ICO file?

ICO (Icon) is Microsoft&#039;s 1985 multi-resolution icon format, originally shipped with Windows 1.0. A single .ico file holds multiple sizes (16×16, 32×32, 48×48, 256×256) so the OS can pick the best one for the current display context. Since 1999, every website uses a favicon.ico to show its icon in browser tabs.

Q: How do I open an ICO file?

On Windows, ICO files open natively in File Explorer and Photos. On macOS, Preview handles basic display. For editing, use GIMP (free), Photoshop with a plugin, or dedicated icon editors like IcoFX.

ARW vs ICO

A detailed comparison of Sony RAW ARW and ICO Icon — file size, quality, compatibility, and which format to choose for your workflow.

Convert ARW → ICO

ARW

Sony RAW ARW

Raster & Vector Images

ARW is Sony Alpha RAW format for professional and mirrorless cameras.

About ARW files

ICO

ICO Icon

Raster & Vector Images

ICO is the icon file format used for favicons and Windows application icons. A single ICO file can contain multiple image sizes and color depths for different display contexts.

About ICO files

Strengths Comparison

ARW Strengths

Full 14-bit sensor data on flagship bodies.
Rich Sony metadata (Creative Style, DRO, Focus Magnifier).
Supported by every major raw processor.
Lossless compression available on modern bodies.

ICO Strengths

Multi-resolution: one file, many sizes, OS picks the right one.
Universal favicon support in every browser since IE5.
Supports transparency (1-bit since 1985, full alpha since XP).
Tiny file size — an entire favicon pack typically fits in under 15 KB.
No licensing or patent concerns — fully in the public domain spec-wise.

Limitations

ARW Limitations

Proprietary — new Sony body launch = Lightroom update required.
Lossy compression was the only option on many older bodies (visible banding in highlights).
File sizes are huge on 50+ MP bodies.
Some ARW variants use 16-bit layout that breaks older third-party tools.

ICO Limitations

Cannot compress continuous-tone images efficiently — use PNG or WebP for photos.
Format is essentially frozen in 1999 — no HDR, no wide gamut, no modern features.
Maximum image dimension is 256×256 px (inside an ICO container).
Editing requires specialized tools — most image editors treat it as a curiosity.

Technical Specifications

Specification	ARW	ICO
MIME type	image/x-sony-arw	image/vnd.microsoft.icon
Extension	.arw	—
Container	TIFF/EP with Sony MakerNote tags	—
Bit depth	14-bit (flagship); 12-bit (entry)	—
Compression	Uncompressed, Lossless, Lossy	Uncompressed bitmap or embedded PNG (Vista+)
Max resolutions per file	—	65 535 images
Max single image size	—	256×256 px
Color depths	—	1, 4, 8, 24, 32 bits per pixel

Typical File Sizes

ARW

24 MP ARW (A7 III, A7C) 25-45 MB
42 MP ARW (A7R III) 50-90 MB
61 MP ARW (A7R IV, A7R V) 75-130 MB

ICO

Classic favicon (16×16 only) < 2 KB
Multi-size favicon pack (16/32/48/256) 5-15 KB
Full Windows app icon set 20-100 KB

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Convert between ARW and ICO online, free, and without installing anything. Encrypted upload, automatic deletion after 2 hours.

Convert ARW to ICO

Frequently Asked Questions

ARW (Sony RAW ARW) is an image format used to store raster graphics — a two-dimensional grid of pixels describing a picture. It is part of the raster & vector images family and designed around a specific trade-off between file size, visual fidelity, and feature support (transparency, colour depth, compression type). Photographers, web designers, and content creators choose ARW when its particular strengths match the publishing target.

ICO (Icon) is Microsoft's 1985 multi-resolution icon format, originally shipped with Windows 1.0. A single .ico file holds multiple sizes (16×16, 32×32, 48×48, 256×256) so the OS can pick the best one for the current display context. Since 1999, every website uses a favicon.ico to show its icon in browser tabs.

Most desktop photo viewers (Windows Photos, macOS Preview, GIMP, Photoshop, Affinity Photo) open ARW natively. On mobile, iOS Photos and Google Photos display ARW in the gallery when supported by the OS. If the format is rare or new, convert to JPG or PNG first — both are universally readable — using our ARW to JPG or ARW to PNG converter.

On Windows, ICO files open natively in File Explorer and Photos. On macOS, Preview handles basic display. For editing, use GIMP (free), Photoshop with a plugin, or dedicated icon editors like IcoFX.

Upload the ARW to KaijuConverter and pick a target format (JPG, PNG, WebP, HEIC, TIFF, BMP, SVG, PDF). The conversion runs in the browser via ImageMagick and returns a download in seconds. No account or installation required; both input and output delete automatically within two hours.

It depends on the task. JPG is the smallest file size for photographs; PNG is lossless with transparency; ARW has its own niche that may favour colour depth, animation, or encoding efficiency over one or both of those. For the final web publish, test all three and measure file size plus visible quality on real content.