A local-first privacy tool

Your page.
Your key.

Protect what matters. Keep the rest open.

One file. No account. No upload.

HTML encryption, private bundles and copy tracing, entirely in your browser.

Understand the protection →

Start with your files

HTML, ZIP or any file for a private bundle.

Drop files hereor choose from your deviceChoose filesUp to 32 MiB of source files · ZIP folders preserved

Choose the protection

The right boundary for your content.

Whole pageA standalone HTML file that opens with a passphrase.Selected sectionsPublic page, private parts. Select existing markers.Private bundleAn encrypted .8zv archive. Read it here.

Separate images, CSS and JavaScript are not automatically inlined or encrypted in page mode.

Set your passphrase

You hold the key. We do not have a recovery copy.

Passphrase

Repeat passphrase

At least 12 characters. Longer and unique is better. Case and spaces matter; “|” is a normal character.

Advanced options

Domain context (optional)

On that hostname, use your passphrase normally. Elsewhere, enter passphrase||domain. This is context binding, not DRM or server authorization.

Additional passphrases

At least 12 characters per passphrase; up to 8 in total. Each opens the same content. The weakest key limits protection.

Key-derivation cost

Higher cost also slows legitimate unlocking, especially on phones.

Compress when it makes the payload smallerRe-run script tags when sections unlock

For your trusted pages only. Section HTML may contain active event attributes regardless of this option. Test the exported page.

Add a removable copy identifier

Clear boundaries. Better protection.

Useful privacy starts with knowing exactly what a tool does — and does not do.

Start in three steps

Choose an HTML file, choose a protection mode, then enter and confirm a strong passphrase. Create, save, and test the output. Keep the original separately.

Mark a private section

<section class="8z-protected"
  data-8z-label="Private notes">
  Your private HTML here.
</section>

Select the detected sections. Outer tags, IDs and all unselected source content stay in place. Also accepts bd-protected. Do not nest protected markers; use explicit closing tags.

For a complete project

A private bundle preserves binary files and folder paths. Restore it in Read, download the ZIP and extract it. It is an archive, not a server or a sandboxed application runner.

What stays local?

The authoring app makes no network requests. No AI proxy, DNS lookup, analytics or external font is used. Only display preferences are stored. Files, keys and your reading library stay in tab memory. A browser password manager may separately offer to save a key.

What is the encryption?

New exports use a versioned v4 envelope: AES-256-GCM, PBKDF2-HMAC-SHA256 (600,000 iterations by default), random salts and IVs, a random content key and separate password-wrapped key slots. Header fields are authenticated. Built-in restoration checks run before download.

This is standard cryptography, not a new cipher, certification or proof of security. Offline password guessing remains possible; choose a long unique passphrase. A public domain name does not add secret entropy.

What is not protected?

An authorized reader can copy the decrypted content and code. Downloaded copies cannot be revoked by deleting the hosted file. External assets are not automatically bundled or encrypted by whole-page mode. Secrets needed by browser code are visible after unlocking; server credentials belong on a server.

Compatibility & constraints

Use a current browser with Web Crypto. HTTPS or localhost is recommended; local-file support depends on the browser. Page and section inputs must be UTF-8. Section mode requires well-formed supported containers and does not auto-edit Content Security Policy. Hosting headers, external resources, app initialization and original scripts need an integration test.

Read supports new v4 files, old Smart whole-page HTML, legacy .8zv version 3, original 500K section files and BD HTML Protector v3 whole pages with the original domain. Legacy section restoration is normalized, not byte-exact. Other historical profiles are not guessed.

Copy identifiers & privacy

Copy marking is optional. It adds a random removable identifier, without rewriting words or adding tracking URLs. Keep the separate recipient manifest private. The tool does not identify people or promise leak attribution.

Origins & release status

Based on BD’s 8Z Shield Smart, the original section engine and BD HTML Protector v3. The original files remain unchanged. This is a release candidate: verify it on your real target devices and publishing environment before commercial launch.

Your page.
Your key.

Start with your files

Ready to share

Your private reading room.

Unlock & inspect

Recognize a copy. Not a culprit.

What does a match tell you?

Clear boundaries. Better protection.

Start in three steps

Mark a private section

For a complete project

Paste HTML

Safe preview

Your page.Your key.

Start with your files

Ready to share

Your private reading room.

Unlock & inspect

Recognize a copy. Not a culprit.

What does a match tell you?

Clear boundaries. Better protection.

Start in three steps

Mark a private section

For a complete project

Your page.
Your key.