---
title: "Web local signatures"
description: "Web local signatures: digital signatures computed locally on a web page with a key on the client side, and why this approach needs care."
canonical: "https://docs.lacunasoftware.com/en-us/articles/pki-guide/web-signatures/local"
locale: "en"
product: "PKI guide"
last_updated: "2026-07-14"
---

# Web local signatures

A *local signature* is a [digital signature](https://docs.lacunasoftware.com/en-us/articles/pki-guide/signatures) performed with a private key that is available
locally and therefore can be performed in a *synchronous* matter (as opposed to remote signatures, which must
be performed asynchronously). For instance, a digital signature performed on the backend with a private key
that is available on the server side would be a local signature (we call these [server signatures](https://docs.lacunasoftware.com/en-us/articles/pki-guide/server-signatures)).

We call a *web local signature* the special case of a local signature performed on a web page
with a key that is available on the client side (i.e. a key of one of the user's
certificates)

As outlined on the article [web signatures](https://docs.lacunasoftware.com/en-us/articles/pki-guide/web-signatures), this approach to implement web signatures should
be considered with care, because performing a digital signature is a complex process that requires network access
to acquire revocation artifacs (Certificate Revocation Lists), which might fail on some users' computers.

**Because of this, on most cases we recommend the [web remote signatures](https://docs.lacunasoftware.com/en-us/articles/pki-guide/web-signatures/remote) approach to implement web signatures instead.**

However, in cases on which files cannot be uploaded to the server under any circumstances, signing locally
on the frontend can be the only option. For such cases, use the **local signature extension** of
**[Web PKI](https://docs.lacunasoftware.com/en-us/articles/web-pki)**. [Contact us](https://www.lacunasoftware.com/en/home/purchase) for details.