PWP to HRZ Converter

Online PWP to HRZ converter — quick results

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Complete Image Extraction

The converter decodes the proprietary PWP format to extract the full image — all the detail Seattle FilmWorks originally processed.

Safe File Handling

Uploaded PWP images are deleted right after processing. Converted outputs are automatically cleaned up within 24 hours.

Just a Browser Needed

No obscure 1990s software required. Open any modern browser and convert PWP files from Seattle FilmWorks instantly.

How to convert PWP to HRZ

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose hrz or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your hrz file right afterwards

About formats

PWP is a proprietary image format used by Seattle FilmWorks (later renamed PhotoWorks) for their internet-based photo delivery service in the mid-to-late 1990s. When customers mailed film rolls to Seattle FilmWorks for developing, the company offered a Pictures Online service that let users download their scanned photos through a dial-up internet connection. PWP files were the format used for these online downloads, containing JPEG-compressed image data wrapped in a proprietary container with additional metadata for the PhotoWorks viewing software. The format was intentionally tied to Seattle FilmWorks' proprietary desktop viewer application (PhotoMail), which customers needed to install to view and manage their downloaded photos. PWP represented one of the earliest attempts at digital photo delivery — bridging the gap between traditional film processing and the emerging internet, at a time when most consumers had no other way to get digital copies of their photographs. One advantage of the PWP format's historical context is that it preserves scanned film images from a transitional era when few consumers owned digital cameras or scanners, making PWP files potentially the only digital record of photographs from that period. The format's JPEG-based internal structure is another practical consideration: despite the proprietary wrapper, the underlying image data uses standard JPEG compression, and tools like ImageMagick, XnView, and dedicated PWP converters can extract the images for viewing in any modern application.
Developer: Seattle FilmWorks
Initial release: 1994
HRZ is a simple raster image format associated with slow-scan television (SSTV), a method of transmitting still images over radio frequencies used by amateur radio operators since the late 1950s when Copthorne Macdonald pioneered the technology. HRZ files store images at a fixed resolution of 256x240 pixels in raw RGB format, with each pixel represented as three bytes (red, green, blue) at 8 bits per channel, producing uncompressed files of exactly 184,320 bytes. The format has no header, no metadata, and no compression — the file is simply a sequential dump of raw pixel data in row-major order. This extreme simplicity reflects the format's origins in the amateur radio community, where SSTV images are transmitted as audio tones encoding luminance and chrominance values over narrow-bandwidth HF (shortwave) radio channels. The fixed 256x240 resolution corresponds to common SSTV transmission modes, and HRZ files serve as the digital capture or storage medium for received SSTV transmissions. One advantage is the format's zero-overhead structure: with no parsing, decompression, or metadata processing required, HRZ files can be read by any program capable of reading raw pixel data with known dimensions — a single function call in virtually any programming language. The format's connection to amateur radio SSTV culture is another notable aspect: HRZ files document a unique form of image communication where operators transmit photographs over thousands of miles using nothing but radio waves and audio encoding, a practice that continues today alongside digital modes. HRZ files can be opened by ImageMagick, GIMP, and specialized SSTV software.
Developer: SSTV Community
Initial release: 1985

Frequently Asked Questions

Why convert PWP to HRZ?

PWP is an extinct proprietary format. Converting to HRZ is likely your only way to view photos that were mailed to you on floppies in the 1990s.

What opens HRZ?

Specialized image tools and amateur radio software handle HRZ format images.

Does conversion lose image quality?

Some quality depends on the target format. HRZ uses specialized encoding, so results reflect the characteristics of HRZ output.

Can I batch convert multiple PWP to HRZ?

Upload several PWP images at once. Each one converts to HRZ independently, and you can download them all when finished.

Is it free to convert PWP to HRZ?

Basic PWP to HRZ conversions are free. Paid plans unlock priority processing and expanded capabilities for heavy users.