If you have the need or desire to use the tools on this site, download a copy of the site, transfer it to an airgapped computer (a computer without internet access and without the capabilities to ever have internet access again - no network cables, no WiFi adapter, etc.) Typing your seed in to a website is just asking to have it, and therefore all your bitcoin, stolen.
Further to that, what you are describing OP gives me serious cause for concern. You say you want to "use your wallet elsewhere" without your Electrum wallet file. This means you don't have your own computer with you, and are instead restoring your wallet on a computer belonging to someone else in order to access your wallet. You absolutely should not do this. Can you be absolutely sure the computer you are using doesn't have a keylogger installed? Or a screen recorder? Or one of thousands of possible viruses or malware? Typing your seed in to someone else's computer is just as risky as typing it in to a website, and you run the risk of all your coins being stolen.
Your seed should remain offline and on paper at all times. It should only touch an electronic device in a dire emergency (when you have irretrievably lost your wallet file or password). If you want to securely carry your bitcoin with you, then buy a hardware wallet.