A stand-in that arrived five weeks after the original was pulled: named "Mod Header", it grew from 155 to 5,000 users in two months

On a Friday in Jul 2026 (10), Google pulled ModHeader, a developer extension used by about 900k people on Chrome, from the store. Five weeks later, on Aug 19, a personal developer who registered with a gmail address uploaded an extension called "Mod Header" with an extra space in the name. It had no website, no social accounts, and charged nothing. By Nov 6 it had 5,000 users. What it captured was an empty search term, which by now has twenty-some stand-ins competing for it. The tactic is worth studying, but this specific case has already been overtaken.

A "Download for Chrome" button that won't open

ModHeader is a small tool almost everyone doing web or API development has installed: it adds or changes HTTP headers on requests your browser sends, for testing logins, feature flags, and CORS. It had about 900k users on Chrome, plus about 1.6M installs on Edge.

The Hacker News coverage on Jul 13 explained the takedown: UK security firm Stripe OLT dissected the store version and found a dormant collector hidden inside. It could fingerprint devices and encrypt and store the domains you visited (up to 1,000), then bundle them daily and send them to api.stanfordstudies[.]com. The switch was an empty list, so there was no evidence it had actually sent data, but a regular update could turn it on. Microsoft pulled the Edge version on Jul 3, and Google pulled the Chrome version a week later. The post on Reddit r/cybersecurity got 65 upvotes and 53 comments, and SC World, cyberpress, and gridinsoft all covered it. Even before the takedown, people on r/webdev complained about its ads, and people on r/foss were promoting alternatives.

As of Nov 6, the original's Chrome store page still redirected to an error page. The modheader.com homepage still says "Used by 800,000+ people", and its "Download for Chrome" button still points to the dead page (11-06 reads). Four months on, people are still searching "modheader" every day, but the store no longer carries the original.

The moment the slot opened, stand-ins lined up to fill it

From the day after the takedown, extensions with ModHeader in their names started appearing in the store one after another (Chrome Web Store, user counts as of early November):

From Jul 12 to the end of July, at least 20 were listed. The established players in the category have been busy too: Requestly (300k users, with a paid tier) wrote a dedicated "ModHeader alternative" page to capture search traffic, and SelectorsHub also wrote a blog post riding the wave.

The main subject of this piece arrived last. It was listed on Aug 19 and had only 1 users by Sep 155.

Five weeks late, how did it still grow?

Per extops.dev's 90-day readings: 9-01 was 155,9-08 at 1.0.8, 435,9-20 at 1,000,10-04, 2,000,10-13 at 3,000,10-22, 4,000,11-01 at 5,000,11-06, and is now 5,000. It grows about 1,000 every nine to ten days, a very straight line. Ratings have stayed at 3 with 5.0 since September and not one has been added. Users grew 30 times over while ratings didn't move at all, which suggests nobody was asked for reviews or incentivized to leave them. The people installing it were developers who found it through search and left after using it. Searching "modheader" on X, nobody mentioned it for 120 days, and no one online recommends it. The traffic came almost entirely from the store itself.

There are three visible reasons the store is sending it traffic.

The name is the exact word users type. Search "mod header" in the Chrome store and 11-06 ranks first, while the same-named extension that launched five weeks earlier ranks second. Same name, yet it gets 5 times as many users, and the difference is in the store listing.

The store page is written for the search box, not for people. Its English description runs 4,500 characters and repeats the same idea in a dozen phrasings: "mod header chrome extension", "mod header chrome", "chrome mod header", "modheader chrome extension", "modheader modify http headers", even the misspelling "mode header chrome extension" is in there. The whole page is segmented with 1️⃣2️⃣3️⃣, 🛠️🌐⚙️ and reads like a keyword list (11-06 store page). It has been translated into 52 languages, and localized descriptions from Chinese, Vietnamese, and Kannada store mirrors have been picked up, so it also surfaces for non-English searches.

It squeezed into the stand-ins' "Related" recommendations. In the "Related" section at the bottom of the store page, it appears in at least 5 similar-extension recommendations alongside ModHeader Extension, ModHeader V3, ModHeader V1, the same-named original ModHeader, and Header Override. The more stand-ins there are, the denser this web of cross-recommendations gets, and anyone caught in it gets a share.

One more bonus: it only requests the declarativeNetRequest and storage permissions (site access is all websites, which header-modifying tools require anyway), and its store page states that it "does not collect or use your data". Users were moving away from the original precisely because it secretly collected data, so this line speaks directly to that concern. However, someone reported that it embeds an umami analytics tracker. That claim is unverified, and it's unclear whether it conflicts with the "no data collection" statement.

Functionally it has nothing special: it modifies request and response headers and toggles rules, like a dozen other stand-ins, and it's weaker than Requestly and Header Editor Lite. It wins on distribution, and the product itself has no advantage.

Who makes it, and the money

The publisher is kainar.toleubaev, registered with a gmail address. The privacy policy is hosted on a Google Doc, and the store marks it as "Non-trader". He also has a Window Resizer (997 users, listed Jul 1), another developer tool, and its store page uses the same "feature name + chrome extension" format. One person with two extensions isn't a scaled clone farm.

On money: no in-app purchases, no website, no pricing, and no revenue ever disclosed. For a developer with 5,000 users to monetize, there are only two routes: build a Pro subscription like Requestly, or add ads or sell data. The second route is exactly why the original was pulled.

How long this slot stays open

Two variables. First, the original could return: modheader.com is still operating and its homepage still carries Chrome, Edge, and Firefox download buttons. If the Chrome version is relisted, searches for "modheader" will flow back to the real product right away, and the stand-ins will drop together. Second, the stand-ins reshuffle among themselves: the one with in-app purchases reached 20k in late October and fell back to 5,000 by November, which shows these users don't stick and rankings churn. The main subject held steady at 5,000 through November without declining, possibly because it works and uninstalls are low (inference).

If it were you

Verdict: Skip this one. The ModHeader slot has been taken since Jul 12, and now more than twenty clones plus established players like Requestly are competing for it. Entering as the 21th one, you'd likely pick up a few hundred users (estimate), with no revenue. The part worth taking is the playbook: when a major extension gets pulled, a clean-permission clone with a matching name, in 52 languages, can capture thousands to tens of thousands of users for free. ModHeader v2 was delisted, then relisted two days later and hit 30k, 6x what this article's subject got.

Who it suits: solo developers who already have the foundation to ship a new extension quickly (MV3 templates, a multilingual store page workflow, experience getting approved within a day), who treat "watch for takedown events" as a standing practice rather than a one-time bet.

Who it doesn't suit: anyone hoping to earn from this. Users of stand-ins like this are developers who arrive through search and leave, without leaving reviews or paying. The only path to revenue is a Pro subscription, which requires being genuinely better than the original, and that's a different business. It's also a poor fit for anyone planning to monetize through ads or data, because that is how the original died, and the store will be watching even more closely.

How to do it: Monitor The Hacker News, BleepingComputer, security outlets like Stripe OLT, and Chrome store takedown news. When an extension with more than 100k users and simple functionality (one or two permissions cover it) gets pulled, move the same day. Use the name users are most likely to type (test with a space, without a space, and with "v2" added), but don't impersonate the original developer. Request the fewest permissions you can, state in the store page that you collect no data, and write out the full range of brand-plus-feature keyword combinations in the description, translated into 50 or more languages.

How to get users: No paid acquisition needed. Rely entirely on store search and the "Related" recommendations. After listing, check on sites like extops and extpose whether you appear in the similar-extension recommendations. Existing users who are already unhappy (for example, about ads in the original) only need one comment in the relevant Reddit community pointing to a clean alternative.

Earlier is better: list within a week of the pull. ModHeader this time: the Jul 12 listing got 30k, the Jul 21 listing got 4,000–5,000. The subject of this piece listed Aug 19, and by stuffing keywords and 52 languages it only caught up with the Jul 21 batch, still six times behind #1. Those few early days mattered far more than how good the store page was.

Signs you're reading it wrong: ① The official ModHeader came back to the Chrome Web Store, and within a month this stand-in fell back below 1,000, so its traffic was borrowed and the playbook only works for a while; ② on the flip side, it was still growing 1,000 every nine to ten days into early 2027, so the brand-name long tail is longer than expected and late arrivals still get a share; ③ the Chrome Web Store has started mass-delisting clones named after other brands, so this playbook has a ceiling.