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Hollow Knight Save Editor

Decrypt, edit, and re-encrypt a narrow set of Hollow Knight PC player-data fields locally: geo, current health, and maximum health.

Hollow Knight PC

01 / Tool workbench

Use the runtime only when it is actually ready.

The application shell fails closed. An input interface is not enabled merely because a WordPress Tool record exists; the declared engine must be registered in the current build.

Hollow Knight Save Editor
BROWSER LOCAL

Checking whether the declared runtime module is loaded. No input has been processed.

Session change summary

No output has been built in this session.

What this game-specific editor changes

Decrypt, edit, and re-encrypt a narrow set of Hollow Knight PC player-data fields locally: geo, current health, and maximum health.

Verified input boundary

The file must use the recognized C# wrapper, exact wrapper length, strict Base64, AES-256-ECB with the documented key and PKCS7 padding, UTF-8 JSON, and a player-data fingerprint containing version/geo/health/maxHealth/playTime.

What is deliberately not claimed

No raw JSON tree editing, mod-specific data synthesis, platform account transfer, cloud synchronization, charm/inventory editing, or malformed-padding recovery is claimed.

Output

A separately wrapped/encrypted .dat copy. Only geo/health/maxHealth numeric JSON values are intentionally changed before the verified container is rebuilt.

Instructions

Close the game, back up usr*.dat, select the file, confirm the version and health values, edit only the exposed fields, and retain the original until the copy loads.

Verification

Verified with independent AES vectors plus deterministic wrapped fixtures, malformed wrapper/ciphertext rejection, numeric relation checks, original immutability, and post-write decrypt/reopen.

02 / Compatibility

Know the supported input before opening a file.

Compatibility fields are intentionally explicit. Missing values stay unclaimed rather than being filled with generic assumptions.

Accepted extensions

.dat

Platforms

PC

Supported versions / editions

Hollow Knight PC usr*.dat C# wrapper/Base64/AES-ECB/JSON family.

Input constraints

The file must use the recognized C# wrapper, exact wrapper length, strict Base64, AES-256-ECB with the documented key and PKCS7 padding, UTF-8 JSON, and a player-data fingerprint containing version/geo/health/maxHealth/playTime.

Known limitations

No raw JSON tree editing, mod-specific data synthesis, platform account transfer, cloud synchronization, charm/inventory editing, or malformed-padding recovery is claimed.

Output / result

A separately wrapped/encrypted .dat copy. Only geo/health/maxHealth numeric JSON values are intentionally changed before the verified container is rebuilt.

03 / Instructions

Use a reversible workflow.

File-oriented workflows start with an untouched original. Tool-specific instructions add only details documented for this utility.

  1. 01Keep the original

    Preserve an untouched copy before creating or transforming binary output.

  2. 02Confirm scope

    Match the file size, format, platform, and version to the support information on this page.

  3. 03Process locally

    Use the runtime only when the page reports that its declared engine is loaded.

  4. 04Validate output

    Compare or test the result before replacing any working source file.

Tool-specific steps

Close the game, back up usr*.dat, select the file, confirm the version and health values, edit only the exposed fields, and retain the original until the copy loads.

04 / Privacy and processing

The processing mode is part of the product contract.

SaveEditor.com should state local processing only when the implementation truly keeps file contents in the browser. Server or hybrid processing must be disclosed just as clearly.

Declared mode

Browser local

Runtime state

Operational

Tool-specific privacy notes

The selected save is processed entirely in the browser after explicit selection. Phase 37 game profile and codec scripts contain no fetch, XMLHttpRequest, WebSocket, or sendBeacon calls. The original bytes are kept immutable; a separate output is produced only after exact profile matching and a successful post-write reopen.

05 / Troubleshooting

When a file is rejected, do not force it.

A rejection can indicate an unsupported size, format, version, platform, or byte sequence. Preserve the original and correct the input instead of bypassing validation.

Wrong file or size

Re-check the documented input type and browser size limit before retrying.

Unsupported format

A generic converter does not imply support for every game-specific container, signing scheme, or serialization format.

Source was modified

Return to the untouched source instead of repeatedly processing a damaged or partially transformed file.

Known Tool issues

Wrong wrapper bytes, length mismatch, invalid Base64/AES padding, invalid JSON, or missing player-data keys fail closed.

06 / Verification

Support claims should be traceable.

The verification date, method notes, and public references are kept separate from marketing language so compatibility can be reviewed over time.

Last verified2026-08-08
Profilehollow-knight-pc-usr-v1

Method notes

Verified with independent AES vectors plus deterministic wrapped fixtures, malformed wrapper/ciphertext rejection, numeric relation checks, original immutability, and post-write decrypt/reopen.

Public references

  1. https://github.com/pipi0118/hollowKnightEditor/blob/main/src/utils/hollowKnightCrypto.ts
  2. https://github.com/ShootMe/LiveSplit.HollowKnight/blob/master/PlayerData/V1568.txt

07 / FAQ

Questions to answer before editing.

These answers are generated from the Tool record and current runtime state rather than generic compatibility promises.

Is Hollow Knight Save Editor ready to use?
The Tool record is verified and declares an operational runtime. The page enables its input controls only when the declared engine module is loaded in the current build.
Does processing stay in the browser?
Yes for this declared mode. The loaded runtime processes the explicit input in the browser; Tool-specific privacy notes describe the exact scope and limits.
Should I keep the original file?
Yes. Keep an untouched source file until any generated output has been validated.
What if my version is not listed?
Treat unlisted versions as unverified. Do not assume two releases use identical save layouts, checksums, signing, or serialization.

Related tools

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Only index-ready verified records from the same Tool Family are shown here.

Related guides

Read the guidance connected to this tool.

Only reviewed, index-ready Guides that explicitly reference this Tool are included.