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.
By the numbers
Figures read directly off the CosLogin site, help center and its live pricing and download configuration endpoints at time of writing.
What CosLogin actually is
CosLogin is a profile manager built 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 draws the product line clearly: CosLogin is the browser, and you pair it with proxies bought from a third-party provider. 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.
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.
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.
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 stays focused on the browser layer and leaves the IPs to your provider.
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, each with a published MD5 hash.
Free tier
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.
Using CosLogin with PROXIES.SX mobile proxies
CosLogin stays on the browser side 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.
The short version
CosLogin gets the fundamentals right. Its Firefox engine is a genuine architectural differentiator in a Chromium-dominated market, offering an alternative approach to browser fingerprint management. The fingerprint documentation is unusually detailed, with per-parameter explanations that help users understand how different settings work. The local automation API is clearly specified with authentication, a consistent response structure, and a ready-to-use Postman example, making integration straightforward. Pricing is fully transparent, including a genuine free tier alongside affordable paid plans starting at $10/month, making it accessible for both individual users and teams. CosLogin is also clear about its scope, pairing with the proxies you already use and recommending a unique IP for each browser profile, which encourages better multi-account management practices.
Overall, CosLogin is a technically solid and well-documented antidetect browser with transparent pricing, practical developer resources, and a free tier that makes it easy for users to evaluate the platform before upgrading.
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. 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".