SCR to JNG Converter
FileFlip converts SCR to JNG entirely inside your browser, using ImageMagick compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert an SCR file to JNG?#
- Drop your SCR file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to JNG and the conversion starts on its own. FileFlip downloads 14.1 MB of WebAssembly the first time and nothing after that, then runs ImageMagick on your own machine.
- Save the JNG file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting SCR to JNG lose quality?#
Yes, once. SCR keeps everything and JNG does not, so this is the first time the file meets a lossy encoder. At high quality the difference is hard to see, and it is worth keeping the SCR original, because every later re-save of the JNG loses a little more.
Is it safe to convert SCR files online?#
Yes, because nothing is uploaded. FileFlip converts SCR files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What SCR to JNG actually does to the file#
Converting SCR to JNG runs on ImageMagick, downloads 14.1 MB of WebAssembly the first time and nothing after that, encodes a lossless source with a lossy encoder for the first time.
| Engine | ImageMagick |
|---|---|
| Conversion path | One step: SCR → JNG |
| Downloaded to your browser | 14.1 MB, once, then cached by your browser |
| Quality | Lossy, first generation |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What is an SCR file?#
An SCR file is a byte-for-byte dump of a ZX Spectrum's display memory, always exactly 6,912 bytes, holding a fixed 256x192 pixel screen the way the Spectrum's own video hardware laid it out.
Use SCR when working directly with ZX Spectrum software or emulators, since it's the format those tools load and save natively without any conversion.
Convert SCR to PNG to view or share a ZX Spectrum screen anywhere outside an emulator or Spectrum-specific tool.
What is a JNG file?#
A JNG file holds a single still image whose colour data is compressed as baseline or progressive JPEG inside the same chunk-based container PNG uses, with an optional PNG- or JPEG-encoded alpha channel for transparency.
There's little reason to create a new JNG file today; the format only makes sense inside an existing MNG animation that already mixes JPEG and PNG frames.
Convert JNG to JPG or PNG for anything meant to display in a browser, since none of the major browsers render JNG natively.
SCR to JNG questions people ask#
What is an SCR file?
An SCR file is a raw snapshot of a ZX Spectrum's screen memory, the exact bytes the Spectrum's hardware used to draw the display. It's always 6,912 bytes: 6,144 bytes of pixel data followed by 768 bytes of colour attribute data.
What programs open SCR files?
ZX Spectrum emulators load SCR files directly into screen memory, and general image viewers like XnView MP can open and convert them. Spectrum-specific paint tools such as ZX-Paintbrush also read and write the format natively.
Why are SCR files always exactly 6,912 bytes?
An SCR file is a direct dump of the ZX Spectrum's fixed-size display memory, which is always 6,912 bytes on real hardware, so the file size never changes regardless of what the screen shows.
What opens a JNG file?
JNG files open in GIMP, Gwenview and ImageMagick-based tools, but no mainstream web browser renders them. That gap is the main reason JNG never spread beyond the small set of software built around the MNG format.