How to add a proxy in Multilogin

Before you paste anything into Multilogin, answer one question: is your proxy authenticated by a username and password, or by having your own address on an allowlist?

Multilogin supports both and the format differs between them, so getting this right first saves the most common failed check. Their own instruction is the same: "Second, determine if your proxy is password- or IP-authenticated".

What is Multilogin?

Multilogin is an anti-detect browser that runs browser profiles with separate fingerprints and network identities. The current product is Multilogin X, which matters more than a version number usually would, and the reason is in the gaps section below.

Their summary of the proxy feature: "Multilogin lets you connect any HTTP, HTTPS, or SOCKS5 proxy in just a few clicks."

Multilogin proxy features

One format, in two lengths

"Enter proxy details in the format IP:port:login:password or IP:port".

IP:port:login:password     password-authenticated
IP:port                    IP-authenticated

The separator is a colon throughout and the credential order is login then password. The error page for a bad paste restates the same string in lowercase, ip:port:username:password, which is the same shape under different names.

Both authentication modes, documented

This is the part to read before anything else.

Password-authenticated: "make sure your proxy details include a username and a password".

IP-authenticated: "make sure your local IP is whitelisted in your proxy provider's dashboard". You then enter the short IP:port form with no credentials at all.

That second mode is worth noting because it is where the tools in this category diverge most. Multilogin documents it as a supported path. AdsPower does not mention allowlisting on any of its proxy pages. And GoLogin mentions it only as a cause of failure, because its checker runs from GoLogin's own infrastructure rather than from your machine.

Proxy lists, capped at 25

"Add a maximum of 25 proxies in the format IP:port or IP:port:login:password". Twenty-five is a hard limit and no file-based import is documented, so a larger pool has to be split.

A proxy template manager

Available on higher tiers, with a "One proxy" option in its Format section. Multilogin gates it: "Available on Pro 50 and higher".

Adding a proxy

1. Work out which mode you have. Password or IP. Do this first.
2. If password-authenticated, paste IP:port:login:password.
3. If IP-authenticated, whitelist your own address in your provider's dashboard, then paste IP:port alone.
4. Save, or press Check proxy, and read the inline result.

When the check fails

"Proxy check failed" is the headline one, and Multilogin's reading of it is blunt: "the root cause found, your proxy is offline, replace it to continue working in this profile or get a new IP". Its counterpart is "Proxy check passed".

"Wrong proxy data" appears at profile launch instead. "It means there's an issue with your proxy, either your traffic is used up or the current IP isn't working." This is also the page where Multilogin restates the required string, which tells you a malformed paste lands here rather than producing an error of its own.

ERR_SOCKS_CONNECTION_FAILED has its own explanation: "it usually means something's up with your SOCKS5 proxy", which Multilogin narrows to misconfigured or offline. The documented workaround carries a trap worth quoting in full, because it is the kind of thing that turns a five-minute fix into an afternoon: switching to HTTP "will likely change the port number, so make sure to update that in your Multilogin profile settings".

ERR_CONNECTION_CLOSED, ERR_CONNECTION_RESET, ERR_TIMED_OUT are page-level errors inside a running profile, and Multilogin's advice is to treat them as proxy problems first.

Four more causes that are not the proxy at all:

• Traffic exhausted, shown as a negative number. "Your proxy traffic may show a negative value", such as -1000 bytes. Multilogin confirms the reading: "It also means that the traffic has run out."
• Local software interfering. "Some apps on your computer, like antivirus programs, firewalls, VPNs, and proxy tools, can mess with Multilogin." Proxifier and SocksEscort are named.
• ISP-level blocking. "Sometimes, internet service providers (ISPs) block proxy providers or even Multilogin itself."
• Clock drift. "If your system time is set manually, it can cause connection issues." Sync the timezone and the symptom goes.

Automating it

Profiles start through a local launcher on port 45001, and the browser port it returns is not stable between launches.

import requests
from playwright.sync_api import sync_playwright

LAUNCHER = "https://launcher.mlx.yt:45001/api/v2"

r = requests.get(
    f"{LAUNCHER}/profile/f/{FOLDER_ID}/p/{PROFILE_ID}/start",
    params={"automation_type": "playwright", "headless_mode": "false"},
    headers={"Authorization": f"Bearer {TOKEN}"},
).json()

port = r["data"]["port"]        # fetch it every time; never hardcode

with sync_playwright() as pw:
    browser = pw.chromium.connect_over_cdp(f"http://127.0.0.1:{port}")
    page = browser.contexts[0].pages[0]
    page.goto("https://example.com")
    browser.close()

automation_type accepts selenium, puppeteer or playwright. In Node the port goes into a loopback URL the same way:

const browserURL = `http://127.0.0.1:${response.data.data.port}`;
const browser = await puppeteer.connect({ browserURL });

Selenium attaches as a remote driver, which is the constraint that catches people porting a script across:

from selenium import webdriver

driver = webdriver.Remote(
    command_executor=f"http://127.0.0.1:{port}",
    options=webdriver.ChromeOptions(),
)

Multilogin is explicit about both traps: "Always dynamically fetch the port from the Multilogin API, avoid hardcoding ports!" and "Selenium, Puppeteer, and Playwright only work with remote WebDriver for Multilogin." They also warn against reusing a closed port and note that firewalls blocking loopback will break this.

Automation scripting is gated to "Pro 10 and higher plans", so the code above follows their documented endpoints rather than a run of ours.

Whichever tool you settle on, the proxy behind it is the recurring cost, and per-gigabyte prices vary far more between providers than these applications vary between each other. What each charges, with the date it was read, is on the provider table.

Limitations

The free plan's allowances do not renew. Five profiles, permanent, no card. The bonuses are one-time and final: "30 mobile minutes and 200 MB of proxy traffic are one-time allowances. They do not renew, and top-ups are not available on the Free plan."

That 200 MB applies only to Multilogin's built-in proxy. A third-party proxy you bring yourself consumes none of it, which makes the free tier more useful for testing your own endpoints than the number suggests.

Twenty-five proxies per list, with no import path.

Automation needs Pro 10, and the template manager needs Pro 50.

What the documentation does not say

This one is unusual, and it is the reason to distrust most other guides on this subject.

Multilogin X's current help centre never names the individual proxy input fields. We read ten proxy-related pages and none contains a quoted "Host", "IP or host", "Username", "Password" or "Login" label. Every current page documents a single combined entry taking IP:port:login:password instead.

The field labels that third-party guides confidently list trace back to docs.multilogin.com, the retired Multilogin 6 knowledge base. That host no longer resolves, and the Multilogin 6 proxy page returns 404. So those guides are describing an interface that is not shipping, and we are not repeating their labels.

Also unestablished from vendor sources:

• Whether SOCKS4 is accepted. Never mentioned. HTTP, HTTPS and SOCKS5 are.
• Whether proxy-over-SSH still exists in Multilogin X. The article covering it is Multilogin 6 only.
• Any fixed CDP port. Multilogin states ports are assigned per launch and declines to publish one.
• Whether the Free plan restricts third-party proxies. The pricing page covers profile limits and traffic bonuses and says nothing about proxy sources.

If your proxy is password-authenticated, one detail is still the provider's to decide: the session token goes in the login segment at some and the password at others. Allowlisting sidesteps it entirely. What each provider states is on its provider page, dated.

Conclusion

Multilogin asks the right question first, and following its instruction to identify your authentication mode before pasting will prevent most of the failures its own help centre documents. Treat the launcher port as per-launch, and be sceptical of any guide that lists Multilogin field labels, because the source those labels come from has been offline long enough to stop being true.