Canonical: https://rom-weaver.com/docs/apply-rom-patches # How to apply a BPS, IPS, UPS, or xdelta patch to a ROM Apply an IPS, BPS, UPS, or xdelta patch to your ROM with the free [online ROM patcher](), then download the patched game. No uploads or account. ## Table of contents - [Patch a ROM in four steps](<#patch-a-rom-in-four-steps>) - [What do you need?](<#what-do-you-need>) - [Add the files](<#add-the-files>) - [Apply a BPS patch](<#apply-a-bps-patch>) - [Apply an IPS or IPS32 patch](<#apply-an-ips-or-ips32-patch>) - [Apply a UPS patch](<#apply-a-ups-patch>) - [Apply an xdelta or VCDIFF patch](<#apply-an-xdelta-or-vcdiff-patch>) - [Apply a PPF patch](<#apply-a-ppf-patch>) - [Apply APS, APSGBA, RUP, and other patch formats](<#apply-aps-apsgba-rup-and-other-patch-formats>) - [Apply an HDiffPatch or HPatchZ patch](<#apply-an-hdiffpatch-or-hpatchz-patch>) - [Dreamcast DCP patches need the CLI](<#dreamcast-dcp-patches-need-the-cli>) - [Read the ROM and patch cards](<#read-the-rom-and-patch-cards>) - [Apply multiple patches in order](<#apply-multiple-patches-in-order>) - [Add cheats to the patch order](<#add-cheats-to-the-patch-order>) - [Choose the output and apply](<#choose-the-output-and-apply>) - [Download one combined patch](<#download-one-combined-patch>) - [Open a weave](<#open-a-weave>) - [If the ROM does not match](<#if-the-rom-does-not-match>) - [Use the result safely](<#use-the-result-safely>) ## Patch a ROM in four steps 1. Open the [online ROM patcher](). 2. Drop your clean ROM and the IPS, BPS, UPS, or xdelta patch into **0x01 Inputs**. 3. Wait for checksumming, then open **Checks**. If the source does not match, [fix the checksum mismatch]() first. 4. Select **APPLY & DOWNLOAD** and save the patched ROM. Your original stays untouched. A `.bps`, `.ips`, or `.ups` file is a patch, not a game: an emulator cannot run it until you apply it to the ROM it was made for. ## What do you need? You need the patch and your own copy of the exact game release it was made for. The files have different roles: - **Original ROM:** the starting game file named by the patch author. Add it to Apply alongside the patch. Keep a clean copy. - **Patch:** a file such as `.bps`, `.ips`, `.ups`, or `.xdelta` that describes changes to the original ROM. - **Archive:** a ZIP, 7z, or RAR that can contain a ROM, a patch, or both. Its extension identifies the archive, not the patch format. - **Output ROM:** the new game file created by applying the patch. You download it and play it in an emulator or on supported hardware. Keep the patch author's notes open and check: - the region, such as USA, Japan, or Europe; - the revision, such as Rev 0 or Rev 1; - the checksum and its algorithm; - whether the ROM has a header; - the order, when there is more than one patch. Compare the checksum, not the filename; [how patching works]() explains why. Changing a patch's format does not fix a ROM mismatch. See [patch formats]() or the [tool comparison](). Without the source file, use **Identify by checksum or game name** below the empty drop zone or in **0x02 ROM**. Search a checksum, or choose a game, system, region, and revision. The card shows locally indexed checksums and size. This search appears only when a weave or patch has not already named the expected source. Keep one clean original somewhere safe. rom-weaver writes a separate result, but a known-good copy makes updates and troubleshooting easier. ## Add the files 1. Open [Apply](). 2. Drop the ROM and patch into **0x01 Inputs**, or choose **Add files**. A folder or [supported archive]() also works; nested archives, CHD, and RVZ are unpacked. 3. Wait for **Reading** and **Checksumming**. If asked, choose the entry the author named. Files dropped on Home, Docs, or What's New offer matching workflows. The resulting cards separate **ROM**, **Patches & Cheats**, and **Apply** controls. To change only the container, use [Compress](). New here? [Your first patch]() supplies homebrew files. [Guided Apply]() waits for your files; **Continue** with none, past the Identify search, loads samples. The [cheats tour]() supplies a sample code. [Input routes]() lists other ways to add files. ## Apply a BPS patch Apply a BPS patch online with the clean ROM its author names. BPS records the source ROM's CRC32, so **Checks** shows a match or a mismatch before you apply; if it fails, follow [Fix a source ROM checksum mismatch](). Choose a plain output file unless your emulator or the patch author needs a compressed format, then [test the result](). For multiple patches, check [order and inputs](<#apply-multiple-patches-in-order>); for output options, see [choose the output and apply](<#choose-the-output-and-apply>). ## Apply an IPS or IPS32 patch Add the `.ips`/`.ips32` and source. These formats contain no source checksum: compare the author's digest using [Checksum]() and check the header state. Successful application alone does not prove the ROM is correct. ## Apply a UPS patch Add the `.ups` and clean source. Check the card's input checks; resolve [region, revision, or header mismatches]() before applying. ## Apply an xdelta or VCDIFF patch Add the supplied `.xdelta`, `.delta`, `.dat`, or `.vcdiff` and the exact image or track named by the author. Source checks depend on how the patch was made; compare any published source digest before applying. ## Apply a PPF patch Add the `.ppf` and exact ROM or track. Check the image layout and checksum; include the CUE and every BIN track for a BIN/CUE disc. For PPF3 undo data, see [Undo PPF](). ## Apply APS, APSGBA, RUP, and other patch formats The same input steps cover APS, APSGBA, RUP, SOLID, GDIFF, PAT/FireFlower, EBP, BDF/BSDIFF40, BSP, MOD/PMSR, DLDI, and DPS. Check the detected format and the author's source digest. The [reference]() lists extensions and creation support. ## Apply an HDiffPatch or HPatchZ patch Add a single-file `.hdiff`/`.hpatchz` and its matching source. Check the author's digest. Directory patches marked `HDIFF19` are unsupported; use the author's directory-patching tool. ## Dreamcast DCP patches need the CLI Use the [CLI DCP procedure](); browser Apply lacks that disc-sheet workflow. Adding a `.dcp` shows a failed patch card that names DCP and gives the CLI procedure's address as plain text, and Apply stays blocked. NINJA1 and PDS cannot be applied. See [support limits](). ## Read the ROM and patch cards The ROM card shows filename, size, system, and checksums. A filename mismatch is advisory; checksum or size mismatches are strict. Open **Checks** for details. Patch cards show format, position, and input/output checks. The three-dot **Patch actions** menu edits details, replaces the file, or removes it. Header controls appear where applicable.

Cropped Apply patch stack with two ordered practice patches in the light theme — Patches run from top to bottom. Each card shows the checks for that step.

Cropped Apply patch stack with two ordered practice patches in the dark theme — Patches run from top to bottom. Each card shows the checks for that step.

## Apply multiple patches in order Patches run top to bottom. Each input selector chooses the state it modifies: keep **Automatic** for checksum inference, **Original ROM** for the clean source, or **Previous patch's result** for the preceding result. Once checks run, **Automatic** shows what they detected, such as **Original ROM (detected)**. Drag a numbered handle to reorder; keyboard users can focus it and follow its announced controls. Switch optional patches **On** or **Off** only in tested combinations. Skipping a required base can break dependent patches. Recheck **Checks** after changing order, inputs, or switches. Input checks describe the authored state. Embedded output checks describe a standalone patch's result, not necessarily the combined stack. [Patch the supplied synthetic CHD]() for a verified example: `01-first.bps` reads the Original; `02-second.bps` requires its output. The tutorial supplies intermediate and final checksums. Use your author's tested states for your own files. ## Add cheats to the patch order To start with a ROM and cheat codes, open [Apply cheat codes](). In **Patches & Cheats**, select **Add cheats to the patch order**, then choose database entries or **Add code manually**. Place each code where it must run; it changes the preceding result. Check game/revision when matching by title, and resolve unsupported-code or write-conflict errors. [Use cheats]() covers validation, export, and offline use. ## Choose the output and apply If **APPLY & DOWNLOAD** is disabled, wait for checksumming and resolve the nearby warning. In **Apply**: 1. Enter a filename without an extension. Characters Windows rejects in file names (`< > : " / \ | ? *`) become spaces, and control characters are removed, in the saved file, archive entries, and cue sheet references; the field keeps what you typed. A name with nothing usable left gets the automatic name. 2. The format selector starts on the ROM's own extension, such as **.gba**, or a ROM-specific format for disc images such as **.chd**. A **.bin** starts on **.chd** only when its contents show a CD image ([content check]()) or a supplied cue sheet names it; a cartridge **.bin** stays on **.bin**. To keep the raw output, pick its own extension, such as **.bin**; a disc with a cue or gdi sheet has several raw files, so its raw choice names them, such as **.bin/.cue** or **.gdi**, and saves them together in one uncompressed **.zip**. Pick **.zip** or **.7z** only if you need a compressed archive; the selector adds the extension. 3. Open **Options** for compression, output header, or weave controls when needed. 4. Choose **APPLY & DOWNLOAD**, wait, and save the new file.

Cropped Apply output card with filename, format, options, and APPLY & DOWNLOAD button in the light theme — Choose the output name and format before applying.

Cropped Apply output card with filename, format, options, and APPLY & DOWNLOAD button in the dark theme — Choose the output name and format before applying.

## Download one combined patch Expand **Download a combined patch**, set its filename and format, then choose **Create patch & download**. It reproduces the enabled patches and ROM cheats in order when applied to your Original ROM. Use one ROM file; multi-file ROMs are unsupported. [Create]() also supports this workflow. ## Open a weave A weave ZIP dropped on Home, Docs, or What's New opens in **Apply Patches** or **Weave Patches**. Add the [weave recipe]() to **0x01 Inputs**, or open the author's preload link. Supply the matching ROM for a patch-only weave, review optional switches, and use **APPLY & DOWNLOAD**. To publish one, follow [Create a weave](). ## If the ROM does not match [Fix checksum errors]() checks region, revision, archive selection, headers, byte order, patch order, and earlier edits. Do not bypass a mismatch to repair it. ## Use the result safely [Test supported ROMs in the browser](), or use your emulator/hardware. Exercise the modified parts; reaching the title screen does not prove every combination works. Keep the clean Original and name the output by project/version. For automation, see [CLI Apply](); to author changes, see [Create a patch](). [Files stay local]().