CosLogin Review 2026
Firefox-engine antidetect browser · desktop client · per-profile proxies · local automation API
CosLogin is a Firefox-engine antidetect browser: a Windows, macOS and Linux desktop client that runs many isolated browser profiles on one machine, each with its own cookies, cache, local storage, fingerprint and third-party proxy. That engine choice is the headline - almost every competitor in this category is Chromium-based, and CosLogin states the Firefox lineage consistently across its homepage, About page, Terms of Service and help center, with the kernel version selectable per profile. Around the browser sit team workspaces (members, groups, role permissions, profile sharing and transfer, recycle bin, cross-device sync), bulk operations for creating, opening, editing and closing profiles, and a documented local HTTP automation API on port 54345 with stated Selenium, Playwright and Puppeteer compatibility. Pricing is published in full, from a real free tier to a $2,500/mo top plan. The gaps are equally worth knowing: the shipping client is version 0.0.2, the site contradicts itself on both price and platform support, and there is no published anti-detection evidence, no refund policy, no SLA and no third-party trust signal of any kind.
By the numbers
Figures read directly off the CosLogin site, help center and its live pricing and download configuration endpoints at time of writing. Nothing here is inferred.
What CosLogin actually is
Strip away the marketing and CosLogin is a profile manager wrapped around a modified Firefox build. You install a desktop client, create profiles, and each profile launches as a separate browser instance with its own storage and its own outbound IP. The point is that two accounts opened in two profiles should not look like the same machine to the platform on the other end - different fingerprint surface, different cookies, different network path.
The help center is refreshingly blunt about the boundary of the product: "CosLogin does not provide proxy IP services. Users need to purchase proxies from third-party providers." It sells the browser and nothing else - no bandwidth, no IP pool, no bundled resale. That makes it complementary to a proxy vendor rather than a competitor, and it also means your anti-linking outcome depends as much on the IPs you bring as on the browser itself.
The site names its own intended use cases: marketplace store management on Amazon, eBay, Shopee, Lazada and Etsy; social account portfolios on Facebook, TikTok, Instagram and X; affiliate marketing and advertising workflows; market research, data collection and automation; retail price monitoring; brand protection; and media and content analysis.
Pricing, as published
CosLogin publishes its full price ladder. The free tier is self-serve - registering grants 10 profiles and 1 sub-account automatically, capped at 50 profile opens per day. Paid plans are a single "Base" card with 13 quantity tiers served live from the pricing API. A Custom plan exists as a calculator (extra members at $2.00 each, an opens ratio of 1,000 per profile) behind a Contact Sales flow.
| Tier | Profiles | Members | Monthly |
|---|---|---|---|
| Free | 10 | 1 | $0 |
| Plan A | 50 | 2 | $10 |
| Plan B | 100 | 4 | $15 |
| Plan C | 200 | 8 | $25 |
| Plan D | 500 | 12 | $50 |
| Plan E | 1,000 | 20 | $80 |
| Plan F | 3,000 | 30 | $140 |
| Plan G | 5,000 | 40 | $200 |
| Plan H | 10,000 | 70 | $300 |
| Plan I | 20,000 | 100 | $400 |
| Plan J | 50,000 | 140 | $800 |
| Plan K | 100,000 | 200 | $1,400 |
| Plan L | 200,000 | 300 | $2,000 |
| Plan M | 300,000 | 400 | $2,500 |
- Daily opens: 50/day on Free, 5,000/day on Plan A, 10,000/day on Plan B. The Custom calculator uses a ratio of 1,000 daily opens per profile.
- Billing periods: monthly, quarterly (10% off), semiannual (20% off), annual (30% off). Plan A annually is $84/year, about $7/mo.
- Extensions: 5 custom extension slots on Free, 10 or more on higher tiers, 50MB maximum each, plus Firefox and local extension support.
- Caveat: the static HTML pricing card still prints a hardcoded "$19 / month" Base headline, which does not match the $10/mo entry tier the live API returns. Verify the number in the client before you buy.
Fingerprint control
Where CosLogin is genuinely strong is documentation depth. The help center carries a separate article per fingerprint parameter - Canvas, WebGL image, WebGL metadata, AudioContext, ClientRects, SSL fingerprint, hardware concurrency, device memory, fonts, WebRTC, timezone, geolocation, screen resolution, device name and MAC address, and launch parameters each get their own page. One-click random fingerprint generation is available if you do not want to tune manually. Profile OS options include mobile simulation (Android, iOS) alongside desktop (Windows, Linux, MacIntel), with a matching User-Agent auto-generated.
Worth stating plainly: mobile OS profiles are fingerprint simulation, not real devices. That is a meaningful limitation for TikTok and other mobile-first platforms the site advertises.
Proxy handling and automation
Proxy support
Bulk proxy configuration is supported, and the anti-linking guide is honest about method: give each account its own profile and its own unique proxy IP, never reuse a proxy across profiles, and retire both the profile and the IP if an account gets restricted.
Local API on 127.0.0.1:54345
POST-only JSON with an X-Cos-Local-Token auth header and a uniform {code, msg, data} envelope. A Postman example is provided, and Selenium, Playwright and Puppeteer compatibility is stated. Docs were last updated 2026-06-18.
Key characteristics
Firefox, not Chromium
The engine is Firefox and the kernel version tracks Firefox releases, selectable per profile. In a category where nearly everything is a Chromium fork, that is a real architectural difference - though CosLogin publishes no evidence that it detects better or worse because of it.
Per-parameter fingerprint tuning
Twenty-plus individually documented parameters, from Canvas and WebGL down to SSL fingerprint, device memory and launch parameters, plus one-click randomisation.
Bring your own proxies
HTTP/HTTPS, SOCKS5, SSH and direct mode over IPv4 and IPv6, pasted as host:port:user:pass and reusable across profiles. CosLogin explicitly does not sell IPs.
Documented local API
Open, close, create, batch-create, update, list and inspect windows, plus group and tag endpoints, over a POST-only JSON API on 127.0.0.1:54345.
Bulk everything
Batch create, open, edit, close and reopen profiles, bulk proxy configuration, bulk cookie import and export, bulk bookmark import.
Real team layer
Member accounts, groups, role permissions, unlimited profile sharing and transfer, recycle-bin restore and cross-device sync, with member capacity tied to the tier (2 on the $10 plan, up to 400 at the top).
Three desktop builds
The live download config serves Windows .exe, macOS arm64 .dmg and Linux .deb, all flagged available at version 0.0.2 dated 2026-07-22, each with a published MD5 hash.
Free tier that actually exists
10 profiles, 1 member, 50 daily opens and 5 extension slots at $0, self-serve on registration. The site warns that creating multiple free accounts trips risk control and forfeits access.
Who it is for
A good fit if
- You specifically want a non-Chromium profile browser and are willing to test whether that helps on your targets.
- You want to evaluate for free before spending - 10 profiles at $0 is enough to test the fingerprint surface and the API.
- You automate: the local API, batch endpoints and Selenium/Playwright/Puppeteer compatibility are the strongest part of the product.
- You read English or Simplified Chinese, and you already have a proxy provider.
- Your budget is tight - $10/mo for 50 profiles, or $84/year on annual billing, is at the low end of this category.
Look elsewhere if
- You need published anti-detection evidence - pass rates, CreepJS or Pixelscan results, competitor benchmarks. None exist here.
- You need a refund policy, SLA or uptime commitment. The Disclaimer explicitly waives warranties on availability, stability and performance.
- You need cloud profiles, hosted browsers or a real Android farm. CosLogin is desktop-only; mobile is simulated.
- Your team works in Russian, Spanish, Portuguese, Vietnamese or Turkish - the storefront is EN and 简中 only.
- You need vendor maturity: the shipping client is version 0.0.2 with no public repo, no named team and no third-party reviews.
Honest limitations
This is the section that matters. Everything below was observed on CosLogin's own site, help center and public endpoints - none of it is speculation, and none of it is disqualifying on its own, but together it defines who should and should not buy.
The site contradicts itself on price
The static HTML pricing card hardcodes "$19 / month" for Base. The live pricing API's cheapest Base tier is $10/mo. Whichever number a visitor remembers, one of them is misleading.
Pricing needs JavaScript and a third-party API call to render
The Base quantity selector ships as an empty element populated from api.coslogin.com. If that host is blocked or slow, visitors see a plan card with no profile count at all.
The download page contradicts the product
/download.html says Windows only, macOS and Linux "coming soon", version 1.0.0 dated 2026-05-22. The live config serves Windows, macOS arm64 and Linux .deb at version 0.0.2 dated 2026-07-22. The help center still tells Mac users to run VMware or Parallels. Nothing on the site says which is current.
The shipping client is version 0.0.2
Whatever the marketing page claims, the actual installer filenames are pre-1.0. This is a very young product, and anyone considering a 3,000-profile plan should weigh that.
FAQ references plans that do not exist
A cloud-sync answer refers to "Pro and Team plans". The actual plans are Free, Base and Custom - a sign of copy assembled from another product's template.
No public repository or SDK
The footer links to github.com/coslogin, which returns 404. There is no open-source SDK and no client library, despite the product leaning on its local API as a selling point.
No payment methods disclosed
No card, crypto, PayPal or regional-wallet indication, no currency options beyond USD display, and no checkout preview. Billing lives entirely behind login in a "Billing Center".
No refund policy, no SLA, no uptime figure
None are published. The Disclaimer explicitly denies warranties on availability, stability and performance, and disclaims liability for data loss from non-renewal, misconfiguration, third-party tools or platform policy changes. Service can be suspended without prior notice for Terms violations.
Anti-detection effectiveness is entirely undocumented
No published pass rates against any platform, no third-party fingerprint-test results (CreepJS, Pixelscan, BrowserLeaks or similar), and no benchmark against Chromium-based competitors. Only assertions that environments are "realistic" and "natural".
The English partner carousel looks fabricated
The English homepage "Trusted Ecosystem Partners" slot shows names - ProxyGrid, NodeHarbor, ExtensionHub, AffiliDesk, AdPilot, SyncLayer - that largely do not correspond to real, identifiable companies; "ProxyGrid" is an alias whose link points to ipdeep.cn. The Chinese homepage in the same slot shows real brands. Showing invented-looking names to English visitors is a transparency problem.
Corporate identity is split and unverifiable
Two entities are named in the footer - 安徽铁脚印网络科技有限公司 and MAIJIN TECHNOLOGY CO., LIMITED - alongside Chinese ICP filing 皖ICP备18020558号-8. No registration numbers, no registered address, no statement of which one is the contracting party or where user data is stored, and no GDPR representative or data-location disclosure.
No independent trust signals
No named founders or team, no customer or user count, no case studies, no Trustpilot/G2/Capterra links, no press coverage. The About page is mission prose with zero verifiable claims.
Bilingual storefront only
English and Simplified Chinese are the only selectable languages, even though the pricing API internally carries 22 locales. Russian, Spanish, Portuguese, Vietnamese, Turkish and others are built but unreachable from the site.
Desktop only, mobile is simulated
No cloud-phone, Android-farm or hosted-browser option. Mobile OS profiles are fingerprint simulation, not real devices - a real limitation for the mobile-first platforms the site advertises.
The free tier is an evaluation trial
50 daily profile opens is a hard ceiling that makes it a trial rather than a workable free plan, and the site warns that multi-accounting the free tier triggers risk control and revokes access.
What is and isn't published
- Published: the full 13-tier Base price ladder plus free tier via the live pricing API, the fingerprint parameter list, supported proxy types and protocols, the local API endpoint reference with auth scheme and Postman example, desktop build filenames with MD5 hashes, Terms of Service, Privacy Policy, a separate Disclaimer, two legal entity names with a Chinese ICP filing, and support via email, Telegram and WeChat. The help center runs to roughly 55 articles, each carrying a last-modified date, most between 2026-06-18 and 2026-07-08.
- Not published: payment methods, refund policy, SLA or uptime figure, anti-detection pass rates or third-party fingerprint-test results, company registration numbers or registered address, data-storage location, GDPR representative, founder or team names, customer counts, case studies, and any third-party review presence. Phone support, live chat and a postal address are also absent.
- Contradictory: the Base headline price ($19 static vs $10 live API) and platform availability plus version number (Windows-only 1.0.0 on the download page vs three platforms at 0.0.2 in the live config).
Using CosLogin with PROXIES.SX mobile proxies
CosLogin does not sell IPs and says so in its own help center, which makes the pairing straightforward: CosLogin is the fingerprint and profile layer, proxies.sx is the network-identity layer. The browser accepts HTTP/HTTPS and SOCKS5 in a host:port:username:password paste format, which is exactly how our endpoints are issued, so setup is a copy-paste per profile with no connector or integration required.
CosLogin
Profile isolation, fingerprint parameters, bulk operations and the local automation API.
PROXIES.SX
A real 4G/5G mobile or residential IP per profile, at $4/GB dropping to $2.40/GB at volume. GB never expire and endpoints are free.
One IP per profile
CosLogin's own anti-linking guide says never reuse a proxy across profiles. Free endpoints make that policy affordable to follow.
Practical setup
- Create a profile in CosLogin and set the OS, timezone and language you intend the account to appear from.
- Paste the proxies.sx endpoint as
host:port:user:passin the profile's proxy field and test the connection before first login. - Keep the profile timezone and geolocation consistent with the exit IP's country - a mismatch is one of the most common self-inflicted signals.
- Assign a distinct endpoint per profile rather than sharing one across many, per CosLogin's own guidance. Since endpoints are free, the only variable cost is the GB you actually use.
- If you drive profiles through the local API on port 54345, set the proxy at create time in the batch payload so a profile never opens on your real IP first.
No claim of certified or tested integration is made here. CosLogin accepts standard HTTP/HTTPS and SOCKS5 credentials, and proxies.sx issues standard HTTP/HTTPS and SOCKS5 credentials - that is the whole of the compatibility story, and it is enough.
Verdict
CosLogin gets the fundamentals right and the presentation wrong. The Firefox engine is a genuine architectural differentiator in a Chromium monoculture, the fingerprint documentation is unusually granular down to per-parameter help articles, the local automation API is properly specified with an auth scheme, a uniform response envelope and a Postman example, and the pricing is fully published - a real $0 tier and 13 paid tiers from $10/mo, which is aggressive for this category. It also tells you honestly that it does not sell proxies and that you should never reuse an IP across profiles, which is better advice than some competitors give.
What holds it back is credibility infrastructure. The site quotes two different Base prices, the download page and the live build config disagree on both platform support and version number, the shipping client is 0.0.2, the FAQ references plans that do not exist, the GitHub link 404s, and the English partner carousel shows names that do not appear to be real companies while the Chinese one shows real brands. There is no anti-detection evidence, no refund policy, no SLA, no payment-method disclosure and no third-party review presence of any kind.
Net: a technically interesting, cheap, well-documented browser from a vendor that has not yet built the trust layer around it. The free tier costs nothing to evaluate and the annual price is low enough that a wrong bet is cheap - so test it against your own targets rather than taking any claim on faith, and pair it with a proxy source you already trust.
Related reviews
CosLogin facts in this review reflect the vendor's own website, help center, Terms of Service, Privacy Policy, Disclaimer and its public pricing and download configuration endpoints at time of writing (verified via coslogin.com and help.coslogin.com). Prices, tier limits, build versions and documentation dates are quoted as published and may change. Items CosLogin does not publish - payment methods, refund policy, SLA, uptime, anti-detection pass rates, company registration details, team names and customer counts - are marked as unpublished rather than inferred, and the contradictions noted (Base headline price, platform support, client version) are reported as observed on the site itself. PROXIES.SX has no certified or tested integration with CosLogin; compatibility rests on standard HTTP/HTTPS and SOCKS5 credential support on both sides. Multi-account activity carries platform-terms risk and readers must comply with the terms of any service they operate on. Outbound links to coslogin.com use rel="nofollow sponsored noopener noreferrer" and carry our referral code.
Contact channels published by CosLogin: support@coslogin.com, Telegram @CosLoginBrowser, and WeChat ID "coslogin". No phone number, live chat or postal address is published.