Inkwell

by Student Radar

Local-first redaction

Redact UK documents on your own device. Nothing leaves your laptop.

Subject Access Requests, safeguarding bundles, FOI responses. Drop in a PDF, get a redacted PDF back with a full audit trail. The document never reaches our servers.

Version 0.1.9Released 2 May 2026

Currently detects

UK identifiers, addresses, names, institutions and high-risk facts.

name{name}email{email}phone{phone}address{address}location{location}institution{institution}postcode{postcode}dob{dob}date{date}id{id}ni number{ni number}upn{upn}uprn{uprn}dbs{dbs}dbs update service{dbs update service}hospital number{hospital number}employee id{employee id}student id{student id}year group{year group}candidate number{candidate number}local authority child id{local authority child id}uci{uci}uln{uln}birth certificate number{birth certificate number}court case ref{court case ref}crime ref{crime ref}cad ref{cad ref}hmcts case ref{hmcts case ref}family court ref{family court ref}card{card}account{account}iban{iban}nhs{nhs}ip{ip}ipv6{ipv6}vehicle reg{vehicle reg}tax id{tax id}passport{passport}driving licence{driving licence}url{url}handle{handle}health fact{health fact}safeguarding fact{safeguarding fact}criminal offence fact{criminal offence fact}religion or belief{religion or belief}ethnicity{ethnicity}trade union membership{trade union membership}political opinion{political opinion}sexual orientation{sexual orientation}disability{disability}immigration status{immigration status}care status{care status}name{name}email{email}phone{phone}address{address}location{location}institution{institution}postcode{postcode}dob{dob}date{date}id{id}ni number{ni number}upn{upn}uprn{uprn}dbs{dbs}dbs update service{dbs update service}hospital number{hospital number}employee id{employee id}student id{student id}year group{year group}candidate number{candidate number}local authority child id{local authority child id}uci{uci}uln{uln}birth certificate number{birth certificate number}court case ref{court case ref}crime ref{crime ref}cad ref{cad ref}hmcts case ref{hmcts case ref}family court ref{family court ref}card{card}account{account}iban{iban}nhs{nhs}ip{ip}ipv6{ipv6}vehicle reg{vehicle reg}tax id{tax id}passport{passport}driving licence{driving licence}url{url}handle{handle}health fact{health fact}safeguarding fact{safeguarding fact}criminal offence fact{criminal offence fact}religion or belief{religion or belief}ethnicity{ethnicity}trade union membership{trade union membership}political opinion{political opinion}sexual orientation{sexual orientation}disability{disability}immigration status{immigration status}care status{care status}

Inkwell desktop app showing local redaction workflow

The problem

UK schools, councils and NHS teams redact thousands of pages a year by hand. Adobe Acrobat sends content to Adobe's cloud. Most online redactors do the same. For documents containing safeguarding notes, medical history or criminal allegations, that's not a tradeoff most DPOs are comfortable making.

Doing it manually takes hours per bundle. Mistakes carry real consequences; a missed name in a SAR response is reportable to the ICO.

Inkwell runs entirely on your device. The detector, the redaction - all of it.

What it does

Find UK personal data in any text.

Names, addresses, postcodes, NHS numbers, NI numbers, UPNs, ULNs, UCIs, hospital numbers, DBS references, driving licences, passport numbers, bank details, dates of birth, and special-category facts under UK GDPR Article 9 and Article 10.

Redact PDFs end-to-end.

Drop a PDF in. Review the suggested redactions. Export a redacted PDF where the underlying text is removed, not just covered.

Stay on your machine.

No upload. No cloud processing. No telemetry of document content.

Why it's different

Built for UK documents specifically. UK postcodes, NHS Mod 11 validation, HMRC NI number rules, DfE pupil identifiers, HMCTS case references, Welsh and Scottish address forms, particle names, and the safeguarding vocabulary that statutory guidance actually uses.

Built by a former SENCO. The categories aren't generic - they map to the things UK information governance teams actually flag, because Stuart AJ spent years writing the documents this tool now redacts.

Built locally by design. The detection engine, the OCR and the redaction all run on your device. We can't see your documents. Neither can anyone else.

How it works

1Drop a PDF into the app, or paste text into the free checker.
2The detector finds personal data using a layered pipeline: deterministic UK-specific rules, validated identifiers (Mod 11 / Luhn / Mod 97), and an optional local language model for context-sensitive cases.
3You review the suggestions. Accept, reject, or add your own.
4Export. The redacted PDF removes the underlying text.

What we don't claim

We do not claim 100% recall. No PII detector reaches it, and ours doesn't either. The reviewer is part of the workflow on purpose.

About

Inkwell is built by Student Radar, a UK company based in Plymouth. Founded by Stuart AJ, formerly Assistant Head and SENCo.

Inkwell is the sister product to Student Radar.

Download the latest version

Choose the installer for your device. Activation codes are issued separately for pilot schools.

Mac Apple Silicon

For Macs with Apple Silicon chips, including M1, M2, M3 and newer.

Inkwell-0.1.9-arm64.dmg · 113 MB

Download

Mac Intel

For older Intel-based Macs.

Inkwell-0.1.9-x64.dmg · 120 MB

Download

Windows

Windows installer for 64-bit Windows devices.

Inkwell-Setup-0.1.9-x64.exe · 151 MB

Download

Inkwell runs locally on your device. Activation codes are issued separately; contact info@studentradar.com if you need access for a pilot school.