Decompress

Upload your compressed sprite data: (file not stored on any server, all calculations are done on your machine)

Make sure to click this button!

Parameters
Offset: In case your data isn't right at the start of the file.
Bank (sets of 16384 bytes)
Offset (within the bank)
You can also just leave the bank as 0 and specify only an offset.
Width of sprite (in tiles)
Height of sprite (in tiles)
Presets:

Options
Expand buffers to fit all graphics available
Horizontally flip the sprite
Size of output image:
Fixed size - 7x7 tiles
Decompression size - Use all tiles
Bounding box size - Use bounding box

You can save the image above by right-clicking and choosing "Save Image...".
You can also download the Game Boy formatted graphics file here!
Compression Ratio = - bytes / - bytes = -

Zoom: Speed: |

Compress

Upload an image to compress into the format used by the generation I Pokémon games!

Don't know what's going on here? Check out the video!

Notes:

Sprite data that is fetched from non-ROM memory is simulated via a snapshot of memory ($8000-$FFFF) while checking a Pokémon's status screen.
The snapshot was taken from the US release of Pokemon Red, so sprites from other games may not be accurate from this region of memory.
The memory region where the decompressed data is temporarily stored is not simulated. All reads return zero, even if the buffer has data in it.

Things to be added:

More localizations.
Scan for back sprites and possibly other sprites.
Simulate reads from the buffer area correctly.

Created by Alex "IsoFrieze" Losego for Retro Game Mechanics Explained
Last updated June 3, 2023 - v1.3.2