---
title: "BLOB Metrics"
slug: "blob-metrics"
updated: 2026-02-03T14:13:14Z
published: 2026-02-03T14:13:14Z
canonical: "learn.servitly.com/blob-metrics"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://learn.servitly.com/llms.txt
> Use this file to discover all available pages before exploring further.

# BLOB Metrics

In case the connected machinery needs to send a file (e.g., an internal log) to the cloud, a BLOB type metric can be used.

The file received will be stored in binary format; it will be up to you how to manage the metric value in the dashboards, for instance, download the file, or parse and display.

## Creating a BLOB metric

To add a new *BLOB Metric* to a *Thing Definition*, you should:

1. Enter the *Raw Data* page.
2. Select the *Thing Definitions* tab.
3. Select the *Thing Definition* to edit.
4. Press the *Add Metric* button.
5. Select the *BLOB Metric* type and provide the required information.
6. Press the Save button and edit the additional information, if needed.

![](https://cdn.document360.io/6759e9c9-3ce3-49df-965a-7231d2d9a10a/Images/Documentation/image(77).png)

## Editing a BLOB metric

A *BLOB Metric* is described by:

## General

- **Name**: the name of the metric, also used to reference it within the dashboards' templates.
- **Description**: the text describing the metric. The description is displayed as a tooltip within the dashboard widgets.
- **Group**: the group the metric belongs to (e.g., Temperatures, System).
- **Metric Sets**: The list of [Metric Sets](/v1/docs/metric-sets) in which this metric is included. Note that, to comply with the [EU Data Act](/v1/docs/data-act-template), all BLOB metrics, when created, are automatically included in the predefined [Raw Data](/v1/docs/metric-sets#raw-data-metric-set) metric set.
- **Privatizable by customer**: allow the customer to define whether the metric is private. For more details, refer to this [Privatizable date](/docs/privatizable-data) article.

## Mapping

The mapping section of a metric you can configure:

- **Path**: the path used to dispatch the incoming messages according to the underlying connection protocol, for instance, in the case of MQTT, this is the last part of the message topic.
- **Content Name**: the name of the property to be extracted from the incoming message payload, which contains the Base64-encoded file.
- **File Name:** the name of the property to be extracted from the incoming message payload, which contains the original name of the file. If missing, the file name will be the metric name.

Refer to the [Encoding Values](/docs/encoding-values#blob-values) article for more details about how to encode BLOB values into payloads.

> [!WARNING]
> BLOB size limits
> 
> The base64-encoded string is limited to 10k characters.

## Displaying a BLOB

A BLOB metric can be displayed only within a [Thing Details](/docs/thing-details) widget or a [Multi Metric List](/docs/multi-metric-list) widget, and the rendered value is the file name that can be clicked to open the file in a new browser tab.