Privacy Tools is a standalone, local-first browser workbench for inspecting image metadata and producing deliberately re-encoded sharing copies. It is part of the add·ideas Toolbox, but the static release also runs independently at any nested path.

Selected files stay in the browser. There are no accounts, analytics, remote lookups, telemetry, or runtime network calls. A source file is never modified.

Version 0.1 workflow

Select or drop a bounded batch. Every file gets a safe display/download name, SHA-256 hash, byte-signature type detection, and claimed-vs-detected type result.
Review categorized findings, parser coverage, dimensions, animation or multi-image status, and warnings.
For a supported static JPEG, PNG, or WebP, explicitly re-encode the decoded pixels. EXIF orientation is normalized; source container blocks, embedded thumbnails, trailing bytes, and source profiles are not copied.
An independently parsed output is mandatory. The result states what was removed, preserved, generated, unsupported, or incompletely checked, and includes source/output SHA-256 hashes and a bounded decoded-pixel sample comparison.
Download an individual re-encoded image, a JSON report, or a ZIP containing re-encoded images and the report. The report itself may be sensitive because it contains source filenames and metadata values.

Format support

Format	Inventory	Deep project scan	Secondary scan	Pixel re-encode
Static JPEG	Yes	EXIF/TIFF, IPTC/Photoshop, XMP, JFIF, ICC, COM, MPF, selected JUMBF/C2PA and trailing bytes	ExifReader	JPEG
Static PNG	Yes	tEXt, zTXt, iTXt/XMP, eXIf/TIFF, iCCP, pHYs, tIME, private/unknown ancillary chunks, selected caBX/C2PA and trailing bytes	ExifReader	PNG
Static WebP	Yes	RIFF/VP8 dimensions, EXIF/TIFF, XMP, ICC, META, animation and trailing bytes	ExifReader	WebP where the browser encoder supports it
TIFF, HEIC/HEIF, AVIF, JPEG XL	Yes	No	Best-effort ExifReader inspection	No
GIF	Yes	No	No supported deep adapter	No
PDF, ZIP/Office, OLE/legacy Office, unknown	Yes	No	No	No

Animation, multi-picture JPEG/MPF, and malformed or partially scanned JPEG/PNG/WebP inputs are inspect-only. Secondary coverage depends on what ExifReader can establish for the particular container. A browser may decode a format it cannot encode; that still does not make it eligible for output.

Findings are grouped as location; people/authorship/rights; dates; device, serial and lens; software/history; document identifiers; comments/titles/ keywords; embedded previews; colour profiles; provenance; technical; or unclassified. Raw XMP is shown only as bounded inert text—never injected as markup.

Security boundaries and limits

Inputs are untrusted. Container parsing runs in a terminable worker and checks declared lengths, CRCs, offsets, TIFF cycles/depth/counts, chunk/segment counts, compressed metadata expansion, dimensions, and aggregate batch size before continuing. Defaults are 100 files, 128 MiB per file, 512 MiB per batch, 4,096 metadata blocks/findings, 8 MiB per metadata block, 4 MiB decompressed metadata, 512-character labels, 16,384-character values, 256 KiB normalized finding text per file, 40 megapixels, a 32,768-pixel edge, and a 256 MiB ZIP payload.

The pixel decode/encode step uses browser-native image and Canvas APIs. It runs only after a complete project scan and bounded dimensions. The output gate does not trust successful encoding: it hashes and scans the newly encoded bytes again. C2PA/JUMBF provenance is authenticity information rather than ordinary tracking metadata; pixel re-encoding removes or invalidates it, and the report calls that out.

This is not an anonymity tool. Metadata removal does not remove visible faces or text, steganography, invisible or forensic watermarks, reverse-image matching, sidecar files, filesystem history, application caches, or cloud and recipient copies. JPEG and lossy WebP output may alter pixels. Colour profiles, resolution metadata, and provenance may be lost. Inspect the actual output and report before sharing it.

See docs/ARCHITECTURE.md and docs/PRIVACY-SECURITY.md for the implementation and threat model.

Browser and accessibility support

Current evergreen Chromium and Firefox are exercised in the browser gate; current Safari is an intended target. JavaScript modules, Web Workers, Blob, Canvas 2D, createImageBitmap where available, and Web Crypto are used. WebP output follows browser encoder support. The application supports the shared Toolbox system/light/dark themes, keyboard file selection, native table and disclosure semantics, visible focus, live progress, and non-colour status text.

Development

Requirements: Node.js 22 or newer and npm 11 or newer.

npm ci
npm run check
npm run test:browser
npm run dev

Vite uses base: './', so dist/ can be hosted at / or below a nested Toolbox path. toolbox-check validates the production manifest and bundle.

Release

npm run release:artifact

This checks the manifest, types, lint, formatting, unit fixtures, production build, Toolbox contract, and Chromium/Firefox workflows, then creates the deterministic release/privacy-tools-0.1.0.zip plus its SHA-256 sidecar. The archive contains the static application, project documents, and exact runtime dependency licence texts.

Licence

Privacy Tools is free software under GPL-3.0-or-later; see LICENSE. Runtime dependencies keep their licences, including ExifReader under MPL-2.0. See THIRD_PARTY_NOTICES.md.