Chrome 151 and the August 31 MV2 Purge: What Actually Happens to Your Extensions

TL;DR

Two dates are getting mashed together in every headline right now, and they mean very different things.

Chrome 151 reached stable on July 28, 2026. Among other changes, it strips the last Manifest V2 developer flags out of Chromium's source. Those flags were already non-functional for normal users — MV2 extensions stopped running on stable Chrome back in July 2025 with Chrome 138. This is source-tree housekeeping, not a user-facing event.

On August 31, 2026, Google removes remaining Manifest V2 listings from the Chrome Web Store. That deletes store pages. It does not reach into your browser and uninstall anything, because anything MV2 in your browser has already been disabled for over a year.

Here's the practical translation: if an extension works in your Chrome today, it is already MV3, and nothing about August 31 affects it. Convert: Web to PDF, Convert: Anything to PDF, and ScrapeMaster have been MV3-native since day one. There is no migration for you to do, no "will it stop working in August" question to answer.

The one thing worth doing before August 31: if you rely on a listing page for documentation, a changelog, or a support link, save it. Store pages that disappear take their content with them.

Untangling the two dates

The confusion is understandable, because the MV2 deprecation has been a four-year drip of deadlines, pauses, and resumptions. Let's put the relevant ones in order.

Notice what's not in that table: a date where a working extension suddenly stops working. That already happened, in July 2025. Everything since has been cleanup of the scaffolding around a transition that was, from the user's point of view, finished.

Why the "uBlock Origin dies in August" framing is a year late

Search interest around "chrome 151 ublock origin" is climbing, and the framing in a lot of coverage is that August is when content blockers get killed. That's not quite right, and the imprecision matters if you're deciding what to install.

uBlock Origin's classic MV2 build stopped running on stable Chrome in 2025. What exists now on Chromium browsers is uBlock Origin Lite, an MV3 build that uses declarativeNetRequest rules instead of dynamic request interception. The MV3 restrictions don't ban ad blocking — they cap how many filtering rules an extension can apply and remove the dynamic, request-by-request blocking that made the classic build so adaptable against fast-rotating ad delivery.

So the honest statement is: content blocking on Chrome got less capable in 2025, and August 31, 2026 removes the store listings of the builds that already stopped working. If you switched to Lite, or to Firefox, or to a different blocker, you made that decision a year ago. Nothing new happens to you next month.

What this means for PDF and scraping extensions specifically

MV3 hit different extension categories with very different force. Content blockers took the hardest hit because their core mechanism — inspecting and modifying every network request in JavaScript — is exactly what MV3 removed.

Extensions that convert pages to PDF or extract structured data were barely affected, for a reason worth understanding:

• They act on the rendered page, not the request stream. Converting a webpage to PDF means reading the DOM after it's rendered and handing it to Chrome's print engine. Extracting a product table means reading the same DOM. Neither operation needs webRequestBlocking.
• The APIs they depend on got better under MV3, not worse. The Side Panel API that ScrapeMaster uses is MV3-only. Chrome's DevTools Protocol path that Convert: Web to PDF uses for Page.printToPDF is unaffected by the manifest version.
• Service workers are an inconvenience, not a wall. MV3 replaced persistent background pages with ephemeral service workers. For a tool that does short bursts of work when you click a button, that's a non-issue. For a tool that needs to maintain a long-lived connection, it's a real engineering cost. PDF conversion is firmly in the first category.

This is why "will my PDF extension survive MV3" was never really the right worry. The right worry, then and now, is whether the extension's permissions are proportionate to what it does.

The permission question is the one that actually matters

MV3 didn't make extensions safe. It made one specific attack surface smaller and left everything else intact. An MV3 extension can still read every page you visit, still phone home with what it finds, and still get sold to a new owner who quietly changes its behavior in an update.

What to actually check, on any extension, MV3 or not:

1. Does it request host permissions for all sites, or only the tab you're on? "On click" activation (activeTab) is dramatically narrower than <all_urls>.
2. Does it make network requests during normal operation? Open DevTools → Network, filter to the extension's origin, and use it. A local converter should show essentially nothing.
3. What does the Chrome Web Store data disclosure say? As of the August 2026 developer policy update, disclosures are more granular. Read them.
4. Who publishes it, and has that changed? Ownership transfers are the most common vector for a good extension going bad.

We wrote at length about auditing this yourself in our guide to scraping and reading CWS privacy disclosures. The short version: an extension that runs entirely locally has nothing to disclose, and you can verify that claim in about ninety seconds with DevTools.

The one concrete action item: archive store listings before August 31

Here's the thing people will actually get burned by. Chrome Web Store listing pages are frequently the only documentation an extension has. Small developers put their changelog, their supported-format list, their known issues, and their support email on the listing and nowhere else.

When those listings are deleted on August 31, that content is gone. Not archived, not redirected — gone. If you're an IT admin who documented an approved-extension list by linking to store pages, or a researcher who cited an extension's stated behavior, or just someone who wants to remember what a now-dead tool actually did, you need a local copy.

How to archive a Chrome Web Store listing properly

Store listings are a React app that lazy-loads screenshots, the description, and the reviews section as you scroll. This is precisely the case where Chrome's built-in Print to PDF falls down — it captures the viewport-rendered state and misses images that hadn't loaded yet.

With Convert: Web to PDF:

1. Open the listing and scroll to the bottom once. Store pages load reviews on scroll; the extension captures what has loaded, so scrolling first is what makes the difference between a two-page PDF and a complete one.
2. Click the extension icon. Use Load All Images so the screenshot carousel and the developer icon are actually in the output rather than showing as gaps.
3. Stay in default mode, not Article Mode. Article Mode runs the Readability algorithm to isolate a main article body — great for news, wrong for a structured product page where the permissions block and version number are as important as the description.
4. If the "Related" carousel at the bottom is noise, use Remove Elements to click it away before exporting. There's an undo if you delete too much.
5. Export at A4 or Letter. The output is a real PDF with selectable text and clickable links, so the developer's support URL stays clickable a year from now.

Do this for every extension in your stack, not just the MV2 ones. It takes about thirty seconds each and it's the cheapest documentation insurance available.

If you need to batch through a list of extension IDs and pull structured metadata — name, version, permission list, last-updated date, user count — across dozens of listings rather than reading them one by one, that's ScrapeMaster territory: point it at a search results page, let it detect the repeating card structure, enable pagination, and export to CSV.

The other Chrome 151 change nobody's talking about

Buried under the MV2 noise: Chrome 151 raises the macOS minimum to macOS 13 Ventura. Chrome 150 was the last release supporting macOS 12 Monterey.

If you're on a Mac that can't run Ventura, you're now on a frozen Chrome build. It'll keep working, but it stops receiving security patches, and every zero-day disclosed from here forward — and there have been five in Chrome this year alone — stays unpatched on your machine indefinitely.

That reframes the "should I use a local extension or an online tool" question for anyone on older hardware. A frozen browser is a worse place to log into a web-based PDF service than a patched one, because the browser itself is now the weak link. It's also an argument for doing conversion locally: fewer sites in the loop means fewer chances for a compromised page to matter.

We go deeper on the practical consequences in Chrome 151 drops macOS Monterey: what it means for your PDF workflow.

How the alternatives handle the transition

Since this is the moment people re-evaluate their extension stack, a quick honest comparison of webpage-to-PDF options.

The dividing line that matters isn't MV2 versus MV3. It's whether the tool needs to fetch the page itself from its own servers, or whether it uses the page already rendered in your authenticated browser session. Server-fetch tools structurally cannot see a page behind a login — they get the logged-out version or an error. That's covered in more depth in our comparison of Chrome extensions and online PDF tools.

What to do this week

A short, concrete list:

• Don't panic about August 31. If your extensions work now, they're MV3 and they'll keep working.
• Archive the store listings you depend on. Especially for niche tools with no external documentation. Thirty seconds each.
• Audit permissions while you're in there. chrome://extensions → Details → Site access. Anything set to "On all sites" that doesn't need to be, change to "On click."
• Check your macOS version if you're on a Mac. If you're below Ventura, you're on a security-frozen Chrome as of this week.
• Stop using MV2 as a proxy for "unsafe." It's a completed migration, not a live risk signal. Permissions and network behavior are the live signals.

Frequently asked questions

Will my extensions stop working on August 31, 2026?

No. August 31 removes Manifest V2 listings from the Chrome Web Store — it deletes store pages, not installed extensions. Any extension currently running in your Chrome is already Manifest V3, because MV2 extensions were disabled on stable Chrome in July 2025 with Chrome 138.

What changed in Chrome 151 regarding Manifest V2?

Chrome 151, stable on July 28, 2026, removed the last MV2-related developer flags from Chromium's source tree. These flags were already non-functional for regular users. It's a source cleanup that affects extension developers, not a behavior change for people browsing.

Is Convert: Web to PDF affected by the Manifest V3 transition?

No. It has been MV3-native since launch. Its conversion path — reading the rendered page and handing it to Chrome's own print engine via the DevTools Protocol — doesn't rely on any API that MV3 removed. The same is true of Convert: Anything to PDF and ScrapeMaster, which uses the MV3-only Side Panel API.

Does Manifest V3 make extensions safer?

Partially, and less than the marketing suggests. MV3 removed blocking webRequest, which shrank one specific attack surface. It did not stop extensions from reading page content, making network requests, or changing behavior after an ownership transfer. Judge an extension by its host permissions and its actual network traffic, not by its manifest version.

How do I save a Chrome Web Store listing as a PDF before it's deleted?

Open the listing, scroll to the bottom once so the lazy-loaded sections render, then use Convert: Web to PDF with Load All Images enabled and Article Mode off. Store pages are structured product pages, not articles — Article Mode would strip the permissions block and version info you actually want to keep.

Why does Chrome 151 require macOS 13 Ventura?

Google raised the minimum supported macOS version with Chrome 151, making Chrome 150 the final release for macOS 12 Monterey. Machines stuck on Monterey will keep running Chrome 150 but will not receive further security updates, including patches for newly disclosed zero-days.

Can I still install an MV2 extension after August 31?

Not from the Chrome Web Store — the listings will be gone. And even if you sideload one, stable Chrome will not run it, because MV2 execution was disabled in July 2025. There's no workaround short of using a browser that never made the transition.

Bottom line

The MV2 story ended in July 2025. What's happening in July and August 2026 is Google sweeping up after itself: source flags in Chrome 151, store listings on August 31. Neither event will break a working extension.

The genuinely useful thing to do with this news cycle is treat it as a prompt to audit what you've got installed — permissions, network behavior, publisher — and to archive any store listing whose content you'd miss. Both take minutes.

Convert: Web to PDF is free, MV3, and runs entirely on your machine — no account, no uploads, no watermark. Scroll the page, click, download. That's the whole workflow, and it hasn't changed across any manifest version.

And if the cleanup mood extends to your evenings: CineMan AI pulls IMDb and Rotten Tomatoes ratings straight onto Netflix, Prime Video, and Disney+ so you stop opening four tabs to decide what to watch. Also free, also MV3, also not interested in your data.