You can sign a document online today in a few minutes — with no installed software, drivers or browser extensions. In this article we go step by step through how to do it safely, while your private key stays on your own device.
Why "without plugins" matters
Until recently, applying an electronic signature meant installing separate programs, libraries or browser extensions. That caused problems: something wouldn't launch, clashed with updates, or required administrator rights.
The modern approach is different. In eObig, signing a document online happens right in the browser thanks to a cryptographic core with a positive conclusion from Ukraine's State Service of Special Communications. You don't need to install anything — just open the site and have your key file and its password.
What you need before you start
Before signing, make sure you have everything ready:
- A qualified electronic signature (QES) key file — usually
.dat,.jksor.pfx, issued by a trust service provider. - The key password — the one you set when obtaining or generating the signature.
- The document you need to sign — already uploaded to the system or created in it.
If you haven't yet figured out what QES is and how it differs from other signatures, start with the piece on the qualified electronic signature.
Step by step: how to sign a document online
Here is the basic signing scenario. The steps are universal for most documents.
- Open the document. Log in to your account and select the document you need to sign, or upload a new file.
- Click "Sign." The system will offer to add a qualified electronic signature.
- Load the key file. Choose your QES file from the list of media or from your device.
- Enter the key password. The password and private key are processed locally, in your browser — they are not sent to the server.
- Confirm signing. The core generates the signature and attaches it to the document. If needed, other participants can sign it too.
- Download or send the original. The finished signed document can be saved, sent to a counterparty online, or kept in the electronic archive.
The whole procedure usually takes less than a minute.
What happens "under the hood" with your key
The key security question is where exactly your private key is processed. In a proper system the answer is unambiguous: only on your device.
| Step | Where it happens | What is sent to the server |
|---|---|---|
| Loading the key | In your browser | Nothing |
| Entering the password | In your browser | Nothing |
| Generating the signature | Locally, on the device | Only the finished signature |
In other words, neither your key nor your password ever leaves your computer or smartphone. For more on the technical side of this process, see the article on browser-based signing security.
Frequently asked questions
Do I need to install anything? No. A modern browser is enough — no plugins, extensions or drivers for the basic scenario.
Can I sign from a smartphone? Yes, the procedure also works in mobile browsers.
Can several people sign? Yes — you can set up a route in which several responsible people sign the document in sequence, and then send it to a counterparty by link (they need no account).
What file format is the key? Usually .dat, .jks or .pfx, depending on the provider that issued it. The system recognizes the common formats automatically.
Is the signed document a legal original? Yes. A document signed with a qualified electronic signature has the same legal force as a paper one signed by hand, so it is accepted by courts, regulators and counterparties.
Try it yourself
Signing online without plugins is fast, secure and legally full. Your key stays with you, and the document immediately gains the force of an original.
Start free at portal.eobig.com or request a demo — and we will walk you through your first signature using your own documents as an example.