Now part of CaptureTools
Lantern now ships inside CaptureTools, one extension holding five separate tools that stay isolated from each other. This page still describes Lantern in full. See the suite.
#DHSeaDev — Chrome MV3 — Side Panel Extension
Lantern
Some things on a page you look for every single time. Mark them once — a word, a sentence, or a whole field — and they are there the next time you open it.
Field Guide
Every highlighter remembers the words you marked. That works beautifully on an article and falls apart on an application, because the thing you actually care about on a job record or an invoice is not a fixed sentence — it is a slot whose contents change. Mark a total of $1,240 by its text and the highlight dies the moment the next record loads.
Lantern treats those as two different jobs, and picks between them from what you did rather than asking. Select some text and it anchors to the words. Right-click a field without selecting anything and it anchors to the field’s label — so the highlight stays on Total when the value changes, and follows you to the next record of the same kind.
Two Kinds of Highlight
- TEXTOne word, a phrase, a whole paragraph — anchored to the words themselves, with the surrounding sentence kept as context so a repeated phrase still resolves to the right one
- FIELDA value in a form or a record — anchored to its label, so it survives the value changing and follows to the next record of the same type
- EITHERChosen automatically — a live selection means text mode, no selection means field mode; there is no setting to get wrong
What it does
One Gesture
Select, right-click, pick a colour. Nothing opens, nothing to configure. The menu leads with the style you used last and the three you use most, so the common case is two clicks and done.
Anchors That Survive
A field highlight is remembered by the nearest label, then by a stable id, then by position, in that order. It holds through a changed value, a renamed CSS class, a re-render, a wrapper element appearing, and a layout rewritten from divs into a table.
It Tells You When It Is Fragile
If a field has no label or stable id nearby, Lantern says so at the moment you create the highlight — while re-picking is still free — rather than letting it quietly stop working weeks later. Anything that has broken is flagged in the panel with a one-click re-pick that keeps your name and colour.
Nothing Leaves Your Device
No account, no sign-in, and no network requests of any kind — not for analytics, not for fonts, not for anything. Lantern only runs on sites you explicitly allow, one at a time, and never asks for access until after you have seen it work.
A Panel, Not a Popup
The side panel stays open while you click around the page, lists every highlight on the current site with its live value, and shows in plain language whether each one is holding or drifting. It is bound to the tab you opened it from, so it never shows you a page you are not looking at.
Share a Set
Export the highlights for one site to a file and hand it to a colleague who uses the same application. Sharing defaults to the current site only, so a file you send does not also list every other site you use.
Under the Hood
The locator, the text anchor, the style sanitiser and the storage schema are pure modules with a headless export, so the logic that decides where a highlight lives can be tested without a browser at all. Six hundred automated checks gate every build — anchoring across mutated copies of the same page, a text-range suite, a sanitiser fuzz pass, two end-to-end session replays, and a schema suite covering corruption, migration and quota.
On top of those sit seven adversarial stress shards, run in isolated workspaces: pathological DOM, hostile CSS values, persistence across simulated browser restarts, and a hand-built model of the Chrome extension platform — permissions, dynamic script registration, service-worker eviction — because the one bug that mattered most could not be caught any other way. It shipped, it was found by hand, and the shard that now reproduces it did not exist until it had already cost something.
Every claim on this page is diffed against the code before it is published. “No network requests” is a grep with zero hits, not an intention.
Built, tested and packaged, with the store listing and assets prepared. Not yet submitted to the Chrome Web Store — the install link lands here the moment it clears review.
Privacy Policy
Lantern collects nothing. Your highlights — the anchors that locate them, the colours you chose, the names you gave them, and the sites they belong to — are written to your browser’s local extension storage and never leave your device. There are no accounts, no sign-in, no analytics, no telemetry, and no advertising.
Data collected
None. Lantern does not collect, transmit, sell, or share any personal information, browsing history, page content, health, financial, location, or authentication data. Nothing is used for advertising, credit assessment, or any purpose unrelated to placing your highlights back on the page.
Network activity
The extension makes zero network requests of any kind: no fetch, no XHR, no WebSocket, no beacons, no remote fonts, and no remote scripts. It runs identically with the network switched off. Nothing is synchronised between your devices, because nothing is ever transmitted. All code is contained in the installed package; no remote code is executed.
Page access
Lantern has no access to any website until you grant it, one site at a time, from its own panel — and it does not ask until after you have already created a highlight and seen it work. Granting a site allows Lantern to read that site’s pages in order to find your highlights and apply their colours. It does not read pages on any site you have not allowed. You can withdraw access for any site at any time from Chrome’s extension settings; your saved highlights are kept so you can re-enable the site later.
What is stored
- A description of where each highlight sits — a nearby field label, an element id, a position, or an excerpt of the text you selected.
- The style you picked and the name you gave it.
- The site address the highlight belongs to.
- Your preferences, such as your most recently used colour.
Page contents are read in order to locate your highlights, and are not stored beyond the small excerpt needed to find a selected passage again.
Your control
Export your highlights for any site to a file, import them back, disable or delete any of them individually or in bulk, or pause Lantern on a site entirely — all from the side panel. Uninstalling the extension removes the stored data with it.
Contact
Questions about this policy: dhseadev@gmail.com