---
title: Download File
description: Download a file over HTTP and measure throughput with a full timing breakdown.
lastUpdated: "2026-09-23"
---

> **For AI agents:** the complete documentation index is at [llms.txt](/llms.txt). Append `.md` to any page URL for its markdown version.

Download a file over the SIM's data connection and measure download throughput, with the complete timing waterfall: DNS, TCP connect, TLS, time to first byte, transfer. The reference action for tracking cellular download performance.

## Parameters

| Parameter | Required | Description |
| ----------- | ---------- | ------------- |
| Url | Yes | URL of the file to download. |
| Ignore SSL certificate | No | Skip certificate verification. Default: off. |
| Enable cookies | No | Keep cookies across redirects. Default: off. |
| Download should fail | No | Invert the verdict, for content that must be blocked. |

Plus the shared [connection settings](/tests/actions/cellular/overview#connection-settings) and DNS override (`command.override_dns`, `command.dns`).

## Results and metrics

In the action report (`result`):

| Field | Description |
|-------|-------------|
| `throughput_in_kbps` | Download throughput. |
| `size_in_bytes` | Bytes downloaded. |
| `status_code` | HTTP status of the response. |
| `md5sum` | Hash of the downloaded file, to verify integrity. |
| `dnslookup_duration`, `connect_duration`, `appconnect_duration`, `pretransfer_duration`, `starttransfer_duration`, `contenttransfer_duration`, `total_duration` | The timing waterfall: DNS, TCP connect, TLS handshake, request, time to first byte, transfer, total. |

In Analytics, each run feeds the HTTP download measurement with `throughput_kbps`, `downloaded_bytes`, every waterfall duration (`namelookup_duration_seconds`, `connect_duration_seconds`, `starttransfer_duration_seconds`...), and `duration_seconds`, tagged by status, URL, status code, APN, antenna, and access technology.

## What's next?

<Columns cols={2}>
  <Card title="HTTP Upload" icon="cloud-arrow-up" href="/tests/actions/cellular/http-upload">

    Measure the uplink direction

</Card>
  <Card title="Ookla Speedtest" icon="gauge-high" href="/tests/actions/cellular/speedtest">

    Both directions plus latency, against Ookla servers

</Card>
</Columns>