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ADOC reader online: how to open an .adoc file and sign an ADOC document

Received an .adoc file that will not open? Load it into the viewer below: you will see what is inside and can download the documents. Further down you will find what the ADOC format is and how to create and sign an ADOC document yourself with a qualified electronic signature (QES).

Need to sign this ADOC?

Add your qualified signature to the original in Tvarka Sign. Sign in, upload the original in Documents, then choose Sign.

Sign an ADOC How to sign an existing ADOC ADOC to PDF

ADOC to PDF: download a readable transcript

Open your ADOC in the viewer above, then choose “Download transcript (PDF)”. The file is sent to Tvarka to check the signatures and generate a PDF transcript, without storing it. Use the transcript for reading, printing or sharing; keep the original ADOC as the signed document. The original electronic signatures remain in the ADOC, not in the PDF transcript.

Need PDF to ADOC instead? Create and sign an ADOC from your PDF with the ADOC wizard.

What is ADOC?

ADOC-V1.0 is the Lithuanian electronic document specification approved in 2009. An ADOC file is not "a document with a signature in the margin" but a container: a single .adoc file packs the content itself (for example, a PDF or text), the mandatory metadata (who, when, on what basis) and electronic signatures in the XAdES format.

The format is used by the Centre of Registers (Registrų centras), courts, municipalities and other public institutions – if an institution asks for a "signed ADOC", a plain signed PDF will not satisfy it.

How to open an .adoc file?

A regular PDF reader will not open an ADOC, because technically it is a ZIP archive with a fixed internal structure. Your options:

• On this page – load the file into the viewer above. It recognises the ADOC structure, shows the main document, the annexes and the number of signatures, and previews PDFs, images and text right away. Everything happens in your browser; the file is not sent anywhere.
• Through a signing service – you upload the .adoc and see the content, the metadata and who signed. Tvarka Sign opens ADOC and lets you extract the files inside.
• Manually – rename the file to .zip and you will see the files in the archive, but you cannot verify signature validity that way, and changing the content will break the document.

How to create and sign an ADOC?

The Tvarka Sign ADOC wizard does the heavy lifting for you:

1. You upload a document or several files.
2. The wizard builds an ADOC-V1.0 container with the mandatory metadata.
3. You sign with a QES: Smart-ID, Mobile-ID, LT ID, a USB/eID card, or by tapping your ID card on your phone (NFC).
4. You download the finished .adoc – ready to submit to the institution.

The wizard is free. Signing with the Lithuanian ID card is free too: 10 qualified signatures a month with no monthly fee of any kind, ADOC documents included. Smart-ID, Mobile-ID and LT ID signatures follow the pricing. Pay for what you use. No subscriptions.

How to sign an .adoc file you received

Since 6 January 2026 the ADOC tool of the Office of the Chief Archivist of Lithuania no longer adds another qualified signature to an existing ADOC document and refers legal entities to other providers. Tvarka Sign signs the .adoc you received: you upload it, the existing signatures and metadata stay intact, and you add your own qualified signature, free with the Lithuanian ID card or with Smart-ID, Mobile-ID or LT ID. You download the signed .adoc with every signature in place. More in the guide Signing an existing ADOC file.

ADOC for institutions and document management systems

Registration, visa and approval signatures, which the state tool dropped in 2026, are created through the Tvarka Sign API under the ADOC-V1.0 specification: your document management system or portal sends the document, Tvarka builds the container, collects the signatures and returns the signed .adoc. No setup fee, you pay per signature. E-signature API comparison · Contact us.

Frequently asked questions

Where does the file go when I load it into the viewer?

Nowhere. The viewer runs in your browser: the file is unpacked and shown on your own device and is not sent to Tvarka's servers. Choosing "Check the signature" or "Download transcript (PDF)" sends the file to Tvarka for that action; the file is not stored.

Does the viewer check whether the signature is valid?

Yes, with one click. The viewer shows the content and the number of signatures, and the "Check the signature" button sends the file to the free signature checker, which shows whether each signature is valid and qualified.

How do I get a PDF transcript of an ADOC?

Load the file into the viewer and click "Download transcript (PDF)": you get a PDF with a signature sheet (who signed, when, whether each signature is valid and qualified) and the document itself, ready to print or forward to anyone who cannot open an ADOC. Keep the original ADOC: its electronic signatures remain in that file. The PDF transcript is a readable copy. Free, the file is never stored.

Received an .adoc from the Centre of Registers, a court or a municipality?

Load it into the viewer at the top of this page: you see the document, the annexes and who signed, and the "Check the signature" button confirms that the signatures are valid. If the institution asks you to sign and return the document, you sign the .adoc you received in Tvarka Sign, and the existing signatures stay.

ADOC or PDF – which one to choose?

Between businesses, a signed PDF or an ASiC-E container is the most convenient. Choose ADOC when you will submit the document to a public institution that requires this format.

Can one ADOC hold several files?

Yes – ADOC is a container, so one signed document can hold the main document and its annexes.

Is an ADOC signature legally valid?

Yes. The QES used inside an ADOC has, under the eIDAS Regulation, the same legal force as a handwritten signature.

You reach the wizard after signing in with your electronic signature – this ensures the document is signed by a person with a verified identity.