Think AI used your work?

English translation produced by the platform. It has not been reviewed by a native speaker and is not a certified translation. The Chinese version is the source.

Version 0.1 | 2026-09-24 | draft walkthrough. Goal: get a recomputable file fingerprint without writing code. If you cannot, skip it for now.

Read this first

A hash lets you check later whether a file's bytes are still identical. It does not replace keeping the original material, the record of how you obtained it, or the basis for the dates.

SHA-256 is not proof of authorship, not proof of when something was created, not a receipt from a platform, not a notarial act and not a court certificate. Two identical fingerprints do not prove a common source, and two different ones may differ only because of a conversion or a metadata change.

Time, cost and tools

Plan 5–10 minutes for small files. Backup time depends on volume. These are estimates, not measured figures.

Your system file manager, a notes app or the writing software you already use: nothing new to pay for; save to the device itself where possible; if cloud sync is already switched on, files may end up in your cloud account.
This site's file fingerprint tool (https://aiusedmywork.org/tools/file-fingerprint.html): free; no registration; no external scripts and no network upload; 64 MiB limit per file; real-device compatibility still untested.

Before you start

Preserve anything in front of you that might disappear before doing anything else. Do not sign out or refresh first.
Do not crop original files or screenshots, do not repair them with AI, and do not fabricate metadata.
Record who actually did the work if someone helps you. Never give a helper your password or a verification code.

Step by step

Step 1 | Open the tool

Where to click: Open https://aiusedmywork.org/tools/file-fingerprint.html in your browser. This page computes on your own device and does not upload files. Do not install an unfamiliar extension that asks to read your whole disk in order to do this.

What you should see: The tool page appears in your browser.

If you can't: If this is awkward on a phone, preserve the work first and record "phone tool not completed". The tool is not a condition of taking part.

Step 2 | Check it is the local tool, not an upload form

Where to click: The page should show a file chooser, a save-report button and a check-an-existing-fingerprint box. It also works offline: it does not need a network.

What you should see: A local tool page, not a form that sends your file somewhere.

If you can't: If you see code or a blank page, try opening it again in a browser. If your browser restricts the local crypto API, do not change your security settings and do not run commands — preserve the original file instead.

Step 3 | Choose a file

Where to click: Under "choose the original file to keep and check", press the button and pick one file from your originals folder, then Open. The button may read "Choose Files".

What you should see: The page lists the file name, its size and the computed result.

If you can't: Anything over 64 MiB (about 67 MB) will be refused. Do not compress your only original or strip content out of it to make it fit. Keep the large file and deal with it later.

Step 4 | Confirm the calculation actually succeeded

Where to click: Check whether each file completed and has a 64-character fingerprint. Anything that errored is not in the successful list. You can practise with a single small file first.

What you should see: Every successful record matches the right file name.

If you can't: If a file cannot be read or the browser does not support it, record the error. Never write out a random 64-character string and present it as a success.

Step 5 | Save the text report

Where to click: When the calculation is done, press "save text report", find the report in your browser's download location, and copy it into the notes folder for that incident. Only use "save JSON manifest" if you are working with someone technical.

What you should see: A .txt report exists, and opening it shows file names, byte sizes, fingerprints, the device time and the stated limitations.

If you can't: A greyed-out save button means there are no successful files — go back and check the previous step. If saving fails on a phone, do not close the page: screenshot the result as a temporary record and note that the report was not downloaded.

Step 6 | Keep the original file — the report does not replace it

Where to click: Keep the report and the original in the same case folder but in different subfolders. Do not delete originals to save space.

What you should see: Both the original and the fingerprint report can be found.

If you can't: If space is short, keep the originals that cannot be obtained again; the report is smaller. Move things carefully to storage you control, and do not share it publicly.

Step 7 | Record the preservation process once

Where to click: In the "Preservation log", write who actually did it, the device and browser, where the time came from, whether you copied, exported or hashed, any malfunction, and the names of the original file and the new copy.

What you should see: The note describes a process, not just a hash.

If you can't: If you do not know the device model, write the general category. Serial numbers and similar details, which a formal Indian certificate may need, are for a later professional step — do not collect them now.

Step 8 | Make a second backup

Where to click: Copy the whole private case folder to another storage medium you control, or to an account you have assessed. Confirm the destination, its permissions and the scope of any cloud sync. A public share link is not a backup.

What you should see: Both places hold the originals and the notes, and you know who can reach them.

If you can't: With only one phone, preserve what you have and record "no second backup yet". Nothing here requires you to pay for an unfamiliar service in order to finish.

Step 9 | Verify one file against the backup

Where to click: In the tool, choose the same file from the backup as the current file. Copy the full fingerprint from the old report into the "previously saved SHA-256 fingerprint" box and press check.

What you should see: If they match, the page says the bytes correspond. That is still not proof of authorship or of a date.

If you can't: If they do not match, keep both copies and look into it — the wrong file, an export format, compression or an edit. Do not overwrite the original and do not alter the old report.

Step 10 | Check again before any formal sharing

Where to click: Open the "Pre-sharing check", and write down the recipient, the scope of the material, the purpose and the date of authorisation. Hash the redacted sharing copy separately and record its parent file. Original metadata may contain GPS or identity information.

What you should see: Only the necessary, authorised material is shared, and the originals stay private.

If you can't: If you cannot confirm permissions, or whether redaction was reliable, do not send it yet. Deleting your sharing copy does not delete copies already sent to others or ones that must be retained by law.

Check when done

The report has not been treated as an independent timestamp or a court certificate.
Large files and failures have not been dressed up as successes.
You at least know where the originals are, and have checked that they open or can be restored.

What you end up keeping

The originals and the local TXT or JSON fingerprint report
The preservation log, and a second backup where practical
The pre-sharing check, before any specific sharing

If something is missing

Over 64 MiB: keep the original, leave the hash field null, and record a tool limit.
The local page is unsupported: you do not need a terminal or new software. Wait for a platform implementation or a verified alternative.
The hashes differ: keep both copies and the record of what you did. A system cannot conclude fraud from this by itself.

Where your data goes, and sharing

Files on your device are not uploaded by this process. Your photo library, iCloud, Google Drive, OneDrive or your editor may already be syncing, so check where something is saved before you save it. An account export communicates with the original service. A full account export is not handed to this project by default.

Keep originals somewhere private. Make a separate copy before sending anything to anyone outside, and check it first for unrelated personal material and for contract restrictions. Share only when the recipient, the purpose and the scope are clear. Nothing is sent automatically in this phase.

When to get professional help

If evidence is about to disappear, if you have received court papers or a deadline, if the chain of rights is unclear, if trade secrets or a minor is involved, or if a formal certificate is required, have a qualified professional in the relevant place check it promptly rather than waiting for this research to finish.

Extra notes for procedures in China and India

China: use the "Handing over to a professional (China)" template at the foot of this page to set out how the material was collected, the devices involved, and why the evidence might disappear. Whether preservation or notarisation is appropriate is for a specific professional check to decide.

India: the "Handing over to a professional (India)" template is a list of facts, not a statutory certificate under section 63 of the BSA. Do not write an expert signature yourself, and do not label this tool's TXT report as court-certified.

Neither country's formal evidence requirements are conditions of being counted as a participant on this platform.

Basis and testing status

Source identifiers: S03, S05, S07, S08, S18, S25, S26. Official URLs and locators are listed on the law pages. The actions in this walkthrough are preservation suggestions, not a claim that the law requires every person to complete every step.

Document checks have been done. Real-device testing on Mac, Windows, iPhone and Android, testing with five non-technical users, and lawyer sign-off have not.

Preservation log

Not third-party certification.

Date and time, and where that came from
Who did it, and who helped (private)
Incident or work number
Source file and source device
Action: copy / download / export / screenshot / hash / backup / verify / share
Destination file or location
Tool and version (as far as known)
Device condition and known faults
Source file size and fingerprint (if you have them)
Destination file size and fingerprint (if you have them)
Do they match: yes / no / not checked
Failures or gaps
Who has access (private)
Start a new entry for the next action — do not overwrite an old one

Pre-sharing check

Not the engagement of a lawyer and not authorisation to litigate.

Named recipient
Purpose
The specific list of files being shared this time
Who authorised it, and on what date
Does it contain unrelated chats, a home address, GPS, a client list, keys or trade secrets
What unrelated material was removed; how the redacted copy relates to the original
Where the original is kept (not shared by default)
Are the recipient's retention and re-sharing rules clear
Is there a clear channel and limit for withdrawing authorisation
If consent is missing or permissions cannot be verified: do not send it yet. You can still keep it locally and take part.

Handing over to a professional (China)

A list of facts for a professional to check. Not a court application, not a notarial deed, not platform certification.

Existing work, rights and incident numbers
Where the evidence is and who controls it
How it was generated, stored, transmitted and extracted
The actual device, app and any known faults
Where the original medium, copies, screenshots and full context are kept
Who operated, the steps, the times and where the time came from
Any neutral-platform original record, existing notarisation or other business records
Specific facts showing the evidence may disappear or later be hard to obtain
Any existing case, intended court, or deadline notice
For the professional to check: the rules currently applicable; whether pre-litigation evidence preservation applies; whether notarisation, expert examination or platform assistance is needed; cost, risk and time limits
Basis: S06 Copyright Law article 57; S07 evidence provisions articles 93–95

Handing over to a professional (India)

FACTS ONLY. Not a section 63 certificate, affidavit, expert report or court filing. Do not sign as an expert. Do not invent device identifiers or claims of normal operation.

Work, incident and file identifiers
Relevant court or proceeding, start date, and any pending earlier proceedings
Person who actually captured or copied the record
Under whose lawful control the record, device or source sits
Known device and application, operating condition and faults
How the specific electronic output was produced
Source and destination file names, size and the actual SHA-256 report (if available)
Dates, local time zones and the basis for the time
Missing facts, and records held by other parties
Sensitive device identifiers: provide only if required, through a secure professional channel
For Indian professional review: BSA applicability, commencement and transitional s.170; s.63 conditions, Parts A and B and the appropriate signatory or expert; applicable case law and timing of submission
Sources: S08; source and version status are listed on the law pages

SOP05 | Produce fingerprints, record the process and back it up safely