Sony ARW MIME Type

What does image/x-sony-arw mean?

The image/x-sony-arw media type identifies Sony Alpha Raw photographs, normally stored with the .arw extension. Sony describes ARW as its own raw format for Alpha and Cyber-shot cameras.¹ An ARW preserves camera sensor measurements and the metadata needed by raw-processing software to turn them into a finished picture. That gives an editor more control over white balance, exposure, color, noise reduction, and sharpening than a camera-finished JPEG.

image/x-sony-arw is a conventional identifier, not an IANA registration. It is absent from IANA's current image registry, while the freedesktop.org shared MIME database uses it for Sony ARW files.²³

How is an ARW file identified?

The .arw filename is the practical identifier. ARW is TIFF-based and usually starts with a TIFF byte-order marker and header, but those opening bytes are shared by ordinary TIFF and several camera-raw formats. They are not a distinctive ARW magic number. A reliable workflow uses the extension, camera metadata, and a raw decoder together rather than treating 49 49 2A 00 alone as proof of ARW.³⁶

An ARW commonly carries:

• Raw or partly processed sensor samples.
• Exif and Sony MakerNote fields describing the capture and camera.
• A camera-rendered JPEG preview that general viewers can display without developing the sensor data.⁶

This structure explains why two applications may show different results. A file browser may display the embedded JPEG, while a raw editor applies its own demosaicing, camera profile, white balance, and tone curve. Renaming an ARW to .jpg or .tif does not convert it.

When did Sony introduce ARW?

Sony's DSLR-A100 introduced the first-generation ARW workflow in 2006. Sony lists the camera's release date as June 6, 2006, and its manual refers to ARW-format data in the supplied Image Data Converter software.⁷⁸

The format remains active. Newer Alpha and Cyber-shot cameras continue to record ARW, with camera-dependent choices that can include uncompressed, lossless-compressed, and compressed raw files.¹⁹ A raw processor may therefore open ARW files from an older body but need an update before it understands a newer model or compression mode.

How to open a .arw file

Use software that explicitly supports the camera model:

• Sony Imaging Edge Desktop is Sony's own viewer and raw developer. It can adjust ARW images and export common formats such as JPEG and TIFF.¹⁰
• Adobe Camera Raw and Lightroom support many Sony cameras. Adobe's compatibility table names the required plug-in version for each model, so extension support alone is not enough.¹¹
• Apple Photos and other system-integrated apps can use Apple's camera-specific raw support on current Apple operating systems.¹²

Chrome, Edge, Firefox, Opera, and Safari do not natively develop ARW as a web image. MDN's browser image-format guide does not include ARW among its supported web formats.¹³ For a website, publish a rendered JPEG, WebP, AVIF, or PNG, and offer the ARW separately when visitors need the original.

Support in Poly

Poly recognizes both .arw and image/x-sony-arw. It also maps .arq files to the same internal Sony-raw category. For either extension, Poly searches the file for embedded JPEG images, chooses the largest decodable candidate within its processing limits, and uses that rendered image to:

• Generate WebP thumbnails and the image-viewer preview.
• Create a visual embedding for similarity and color search.
• Give the Poly agent an image it can inspect.

Poly separately parses available image metadata from the first 1 MiB of the file. It indexes the filename and extracted properties alongside the visual embedding. It does not demosaic or color-develop the raw sensor samples, and it does not OCR text visible in an ordinary image. The preview can therefore differ from Sony Imaging Edge or Adobe Camera Raw, particularly when the embedded preview reflects different camera settings.

The agent normally receives the largest generated WebP thumbnail whose longest edge is at most 1536 pixels. It can reason about that rendered view, but it cannot inspect the original raw mosaic, reconstruct clipped data, judge raw-level focus, or enumerate every component image in an ARQ composite.

Converting ARW for editing or sharing

Choose the destination based on what must survive:

Sony Imaging Edge can develop ARW files to JPEG or TIFF.¹⁰ Keep the original ARW after export. A rendered derivative records one interpretation of the capture and cannot recreate all of the original sensor measurements later.

What is the difference between ARW and ARQ?

ARQ is related to ARW, but it represents a different workflow. Sony Imaging Edge creates an .arq file by combining multiple .arw captures from Pixel Shift Multi Shooting. Sony documents four-image and sixteen-image capture modes, depending on the camera.¹⁰

Poly accepts both extensions as image/x-sony-arw, but its preview path still selects one embedded JPEG representation. It does not expose the ARQ's component captures or perform Sony's pixel-shift development.