tools
Use them on their own, no account needed.
Part of Paramant is simply a set of tools: you open a page, do what you came to do, and close it again.
01
No account.
no sign-up
no payment
no payment
works right away
Lock a file
Choose a file and a passphrase. Your browser turns it into a locked file that only opens again with that passphrase.
The file and the passphrase stay on your own device. We never receive them, so we cannot recover the passphrase for you either. If you lose it, the file is gone.
Lock a fileThe technical detail
AES-256-GCM. The key is derived from your passphrase with PBKDF2-SHA-256 over 600,000 rounds, with a random salt and nonce. The number of rounds is stored in the file itself, so older files keep opening. The page makes no network request at all.
works right away
Check a signature or a delivery receipt
Put a signed document next to its signature file, or open the receipt of a transfer. The page works out whether it holds.
The check runs in your browser, even offline. One exception: signatures in the old format can only be checked by the server, and that needs a key. The page tells you when that is the case.
Check somethingThe technical detail
For the current format, SHA3-256 is computed over your document, then the ML-DSA-65 signature over that hash is checked, and then the validity period. A receipt is checked against keys that are built into the page itself. In both cases not a single request leaves your device.
works right away
Read the public log
Every registration of a public key is added to a log that can only grow, and that anyone may read.
You see hashes and times. Documents, file names and the names of people are not in it, and cannot be derived from it.
Open the logThe technical detail
A Merkle tree stored on disk that survives a restart. The public view rounds times to the hour. On 5 September 2026 it held 891 entries.
you need a link
Pick up a file someone sent you
If someone sent you a Paramant link, you pick up the file here and your browser opens it again.
You cannot start anything here yourself. Without a link from a sender there is nothing to pick up. A link from the web app opens once; after that our copy is gone.
Open a linkThe technical detail
The key sits after the # in the link. A browser never sends that part of an address to a server, so we do not have the key and cannot open the file. The file name is encrypted inside the file itself and is not stored next to it.
Checked against the code and against paramant.app on 5 September 2026
02
These do need an account.
free account
said up front
said up front
These two need an account. An account costs nothing: the Community plan is free and stays free. It is said here so you know before you choose a file, not after. Both buttons therefore go to the sign-in screen first, and then straight on to the tool.
account needed
Have a document signed
Prepare a PDF, place your signature and sign it, or send the document to the people who need to sign.
Preparing the document and placing the signature work without signing in; the signing itself does not. The Community plan gives two signatures a month.
Sign in first, then signaccount needed
Send a file securely
Encrypt a file in your browser and hand it over live to the recipient, or leave it behind a link that expires by itself.
This page asks you to sign in first, so without an account you cannot get in. The Community plan gives fifty transfers a month. A live transfer can carry a file of up to 500 MB; a one-time link is a single sealed block and takes up to 5 MB per file.
Sign in first, then send03
What comes after.
four steps
no hurry
no hurry
Tools
The tools above cost nothing, and what works without an account today keeps working without one.
Firm
29 euros a month, excl. VAT, for a whole office instead of per user: one hundred signatures and five hundred transfers a month, and access to the API. The full price list.
The monthly measurement
From 250 euros a month I measure every month, in the same way, what your site or app sends out, and what changed in that since last month. The work is done in Dutch. Ask about it.
Research to order
One question, one investigation, a fixed price agreed in advance. Ask about it.