Router Password Requirements
Why your new password keeps getting rejected — and how to fix it
You generated a strong password, pasted it into your router's admin page, and got an error like "The password contains invalid characters." It's one of the most frustrating parts of securing a router — and it's almost never about strength. It's about which special characters the router firmware happens to allow.
Why routers reject strong passwords
Most password generators include the full symbol set: ! @ # $ % ^ & * ( ) [ ] { } | < > ? / ~ `
and more. But many router admin panels only accept a subset of these, because their firmware
parses the password in ways that break on certain characters. If your generated password contains even
one disallowed symbol, the whole thing is rejected — no matter how strong it is.
Example: TPG and similar routers
TPG-branded routers (and many others) commonly allow only this set of special characters:
That means symbols like < > ! @ # $ % & ( ) [ ] | and ? will cause a
rejection. Many routers also require the length to be within a specific range (often 14 to 16
characters) and to include at least one uppercase letter, one lowercase letter, one number, and
one allowed symbol.
The fix: generate a router-safe password
Our password generator has a built-in "router-safe symbols" option. Turn it on and it restricts the symbol set to the characters routers accept, keeps the length in the 14–16 range, and still guarantees one of each required type — so it saves on the first try.
- Open the Password Generator
- Click Advanced Options
- Click 🛡️ Use router-safe symbols
- Copy the result into your router's admin page
You can also paste your router's exact allowed characters into the Custom symbol set field if it differs from the default — useful for Netgear, TP-Link, ASUS, or ISP-supplied modems that publish their own rules.
Still failing? Quick checklist
- Check the length limit — some routers cap at 16 characters.
- Avoid
'"and\if it still fails; a few firmwares mishandle these even when "allowed." - Make sure you didn't paste a trailing space.
- Confirm you have at least one uppercase, one lowercase, one number, and one allowed symbol.