---
title: "CDN Prewarmer: Pre-cache Streams Across Edges"
url: https://ireplay.tv/tools/cdn-prewarmer
markdown_url: https://ireplay.tv/tools/cdn-prewarmer.md
description: "Pre-warm your CDN edges before a live event or big release so the first viewers never hit a cold cache. Free CDN prewarming tool from the iReplay.tv collective."
type: tool
site: iReplay.tv
---

# CDN Prewarmer: fill every edge cache before the first viewer arrives

The first viewer of a new VOD asset pays for everyone else: their player requests a segment, the edge has never seen it, and the request goes back to origin while they wait. The iReplay.tv CDN Prewarmer removes that penalty by fetching every segment of every variant ahead of time, which forces each CDN edge to pull from origin before an audience is watching. By the time real viewers arrive the caches are warm and playback starts without the cold-start stall.

## How to use it

- Paste an HLS or DASH manifest URL and set a timeout.
- Choose how much of the asset to prefetch across all quality levels: the opening minutes are often enough, since that is where abandonment happens.
- The tool walks the manifest, enumerates every rendition, and requests the segments so the edges pull them.

It is for VOD streams only. A live stream produces new segments continuously, so there is nothing to warm ahead of time; what matters there is the edge topology, which is what the [Streaming Cost Optimizer](https://ireplay.tv/tools/cdn-optimizer) addresses. Prewarming a badly packaged stream only caches the problem faster, so it is worth checking the stream against best practice with the [Streaming Analyzer](https://ireplay.tv/tools/stream-analyzer) first. Sign-in is required, and the tool is free. iReplay.tv is run by a collective of streaming and broadcast engineers; you can also [hire streaming and broadcast specialists](https://ireplay.tv/media-streaming-broadcast-talents).

---

Source: [CDN Prewarmer: Pre-cache Streams Across Edges](https://ireplay.tv/tools/cdn-prewarmer) on iReplay.tv. The HTML page is the canonical one to cite, and the only place the tool actually runs. Free to quote and cite with attribution and a link to the source URL.

Every iReplay.tv tool, one line each: https://ireplay.tv/llms.txt