Patch a GBA game with your BPS or UPS file
Check your own GBA input against your BPS or UPS patch before applying it. Stop on a mismatch or an already patched result; do not force it through.
Checked 18 Oct 2026 against our patcher code and generated-header fixtures.
Written by AI from this site’s checker and patcher implementation; checked with original generated inputs and built-page checks, not by playing. How we check
These steps describe this site’s tool code and original practice fixtures, not a game or device test. Each input must be at most 64 MiB. IPS, xdelta, GB, GBC, DS and fangame installers are not supported by this route.
Apply your patch
Keep your original base, working game and in-game save separate. Read the creator’s required game, region, revision and save rules; a filename is not proof of the right bytes. We never supply ROMs or patches.
Open the local ROM patcher. To inspect a header or compare a full-file checksum first, use the ROM checker.
In the ROM patcher, choose your own input under “Your GBA file”.
Your selected game’s name appears. If it is an archive, extract it on your device and select the actual GBA file; renaming an archive does not extract it.
Under “BPS or UPS patch”, choose the patch for the exact edition you intend to use.
Both selected filenames appear. If the format is rejected, stop and use the creator’s stated tool; changing an extension does not convert a patch.
Choose “Check files”.
The result shows the header claims, actual input and required source and target size and CRC32. CRC32 is a checksum of the file’s bytes. Read the matching result below before continuing.
In “Game name, without version or extension”, enter a stable game name.
The proposed output name appears. For an update, match the working game’s filename stem, but keep a separate backup. A matching name does not prove save compatibility.
Choose “Apply patch” only when the input matches and the button is enabled.
The patcher rechecks the inputs and checks the full output. A failed check offers no file. Keep both selected inputs and use the exact error, not a checksum bypass.
Use “Save patched game file” when the checked output appears.
Save it separately from your working game. Inspect the filename actually saved; the browser may alter a duplicate name. A save link is not proof that a file reached your device or that the game runs.
Read the first result that applies
The input matches the required source
Size and CRC32 agree with the selected patch. Continue with naming and applying; this does not prove the patch’s creator, game version or save compatibility.
The input matches neither source nor target
Stop. Compare the header claims and whole-file values with the creator’s exact base requirement. Check the patch edition before trying another input. Do not edit a header or disable validation.
The input matches the target
Do not apply this patch again: UPS can undo a patch. Keep that file separate and establish what it is before launching it; the match alone does not identify the game or version.
A shorter input matches after padding
Under “Padding for a copy of this shorter input”, choose only a matching 0x00 or 0xFF option shown by the patcher. It pads a copy and rechecks it before applying. If no option matches, stop. This is not a verified clean-base identification.
The patch or output check fails
Keep the originals. Read whether the error names a damaged patch, invalid instruction or output mismatch. No output is offered; do not try to repair the result by renaming it.
Try without game files
Both practice options create headers and a BPS patch here. They contain no Nintendo logo or game data. A checksum match in this practice is not a game or device test.
In the patcher, choose “Try header practice”.
The practice name and generated inputs appear, then the input check runs. Apply the patch; the expected output is 512 bytes, not a playable game.
Choose “Try shorter input”.
The generated input is 384 bytes; the required source is 512. Choose the matching 0x00 padding option, then apply. The checked output is again 512 bytes; the original input is unchanged.
Keep the output and save separate
Patching, saving the output and running a game are separate steps. Open the saved game output, not the patch, using the creator’s stated setup. Do not move an existing save unless that exact version pair has a documented migration rule. Keep the working game and save if the rule is unknown.
Did this fix it?
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Need help with the exact message? Read checksum and input-message help.