Extension Pulse, week of July 6: 120 more countries can publish, and unlimitedStorage still has no ceiling

This is the first Extension Pulse on the blog. Same notes I send in the Monday email, written as something you'd actually want to read rather than a changelog dump.

The useful story this week isn't another Chrome milestone date. It's that Google is about to let a lot more people publish, while the standards group that is supposed to put a ceiling on unlimitedStorage spent an hour and agreed on nothing.

The store is about to get more crowded

At I/O 2026 Google said Chrome Web Store developer registration is expanding to over 120 additional countries this year. No day-of-the-week. Just "2026." Monthly registrations have already more than doubled, according to the I/O recap on developer.chrome.com.

If you ship a productivity tool, a language pack, or anything with a local-service angle, that's new supply in your category. If you live in a country that couldn't register a CWS publisher account last year, it's the first time the front door is supposed to open.

Same recap: Chrome Web Store now has private enterprise publishing — you can push an extension to an external org without listing it publicly. That's the quiet half of the announcement. The noisy half is 120 countries. The durable half is enterprises finally getting a store-native private channel instead of sideload theatre.

unlimitedStorage: still unlimited

The W3C WebExtensions Community Group met on July 2 to triage Safari's proposal for a 1 GB per-call cap on storage.set() / storage.get() for extensions with unlimitedStorage (WECG #1028, minutes in PR #1037).

Safari wants 1 GB, uniform on iOS and macOS, because iPhones kill processes that get greedy. Firefox already has a ~256 MB IPC ceiling, so any agreed number has to be something they can actually enforce. Chrome's line, paraphrased: we'd like metrics before we put a hard limit in.

No consensus. No timeline. Rob Wu (Mozilla) flagged the obvious backwards-compat mess: a new cap breaks extensions that already send large payloads. Someone suggested exposing the limit to developers; someone else noted that leaks free disk space.

I wrote up what unlimitedStorage actually does — and the ~687 million users sitting behind it — in unlimitedStorage explained. This week's meeting didn't change that number. It just confirmed nobody wants to go first.

Firefox 153 is an ESR, and file access is about to get awkward

Firefox 153 is scheduled around July 21, and it's the next Extended Support Release. Enterprise fleets that lock to ESR will live on the 153 API surface for roughly 15 months.

The change I actually care about on that train: file access becomes opt-in, including for add-ons you already installed. I counted 842 Firefox add-ons that request file:// in Firefox is about to make file access opt-in. If you maintain one of those, July 21 is not "we'll see." It's a support ticket generator.

Smaller, but it'll bite themers: Firefox 152 dropped the automatic greyscale/brightness CSS filter on SVG pageAction icons. If your address-bar icon relied on the browser to look disabled, you now style that yourself.

Also this week

• Chrome 151 entered beta (July 1). Full stable is July 28. That's the release that deletes the last MV2 feature flags — more on that when it actually ships.
• WECG is still talking about deferrable_permissions (a third proposal for "ask me later" permission UX) and transferring the webextensions repo from @w3c to @w3c-cg for IP hygiene. Process, not product.
• Chrome 155 / 156 dates showed up on Chromium Dash (stable October 6 and October 20). Calendar noise; I'll mention them when a CL actually lands in those milestones.

What I'd do this week

If you ship on Chrome and you're in a newly eligible country, watch the publisher signup page — Google didn't give a date, so the leading indicator is "can I register yet."

If you use unlimitedStorage to shuttle big blobs through storage.set, assume a cap is coming and chunk now. Waiting for Chrome's metrics program is how you find out from a bug report.

If you have a Firefox add-on that reads local files, test 153 Beta with the new opt-in. Don't discover it on ESR day.

And if you're still on Manifest V2 on Chrome: Chrome 150 already killed runtime. The store purge is August 31. The Manifest V3 generator will at least get a valid MV3 shell in front of you; @extenshi/cli (npx @extenshi/cli) flags MV2-era patterns before you upload. Five scans a month are free, prepaid packs after that.

Sources

• "What's new in web extensions: I/O 2026 recap", Chrome for Developers, 2026-05-22
• Firefox 153 release notes, MDN / Mozilla, 2026-07
• Chrome milestone schedule, Chromium Dash — Chrome 151 stable 2026-07-28

Methodology

Signals are the docs under forecasts/signals/ dated 2026-06-29 through 2026-07-06 — the same 7-day window the newsletter uses. Chrome milestone-schedule rows (M155, M156) are folded into one calendar note. Listing counts and MAU estimates come from Extenshi store snapshots at event time; a Chrome-stable row covering ~265k listings is the catalog's Chrome universe, not "every user is broken."

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This issue of Extension Pulse is compiled from vendor docs, WECG minutes, and Extenshi catalog snapshots. We don't independently verify every upstream claim. If something here is off, tell us at [email protected].

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