--- title: "What Is RTMP? Real-Time Messaging Protocol Explained" description: "RTMP is the protocol most live encoders use to send a stream to a platform. See how it works, its limits and how it compares with SRT." url: "https://www.rentanott.com/glossary/rtmp" markdown_url: "https://www.rentanott.com/glossary/rtmp.md" category: "Streaming technology" updated: "2026-10-05" --- # What is RTMP? RTMP (Real-Time Messaging Protocol) is a protocol for sending live video and audio over the internet with low delay. It was created for Flash video and is now used mainly for contribution: carrying a live feed from an encoder to a streaming platform. ## How RTMP is used today The platform gives you an ingest address and a stream key. You enter them in your encoder, which opens a persistent connection and pushes the stream. The platform receives it, transcodes it into several qualities and delivers it to viewers over HLS or DASH. RTMP is no longer used to reach viewers. Browsers dropped Flash, and segment-based protocols scale far better through CDNs. ## Variants - RTMP: the basic protocol, unencrypted - RTMPS: RTMP over TLS, encrypted in transit; the version to use - Enhanced RTMP: a newer extension adding support for codecs such as H.265 and AV1 ## Strengths and limits - Strength: supported by virtually every encoder and platform - Strength: simple to set up, with a delay of only a few seconds - Limit: built on TCP, so it stalls and falls behind on a lossy connection - Limit: classic RTMP carries only H.264 video and AAC audio - Limit: weak support for multiple audio tracks and modern metadata ## RTMP vs SRT SRT is a newer contribution protocol that runs over UDP with its own error recovery and built-in encryption. It holds up much better over unreliable networks, such as a venue's shared internet or a cellular link. RTMP remains the default because it is everywhere; SRT is the better choice when the network is the risk. ## RTMP on RentAnOTT Live channels and events are included on the RentAnOTT Growth and Scale tiers and are a $119/month add-on on Launch. For what sends the feed, see the live encoder entry. [Read about live encoders](https://www.rentanott.com/glossary/live-encoder). ## Related terms - [Live encoder](https://www.rentanott.com/glossary/live-encoder) — A live encoder is the hardware or software that takes a live video feed from a camera or production mixer, compresses it in real time and sends it over the internet to a streaming platform, most often using RTMP or SRT. - [HLS](https://www.rentanott.com/glossary/hls) — HLS (HTTP Live Streaming) is a streaming protocol created by Apple that delivers video as a series of short segments over ordinary web servers, listed in playlist files with the .m3u8 extension. It is the most widely supported way to stream both live and on-demand video. - [Live streaming](https://www.rentanott.com/glossary/live-streaming) — Live streaming is delivering video over the internet as it is captured, so that viewers watch an event while it is happening, with a delay of a few seconds rather than after a recording has been uploaded. - [Streaming protocol](https://www.rentanott.com/glossary/streaming-protocol) — A streaming protocol is a set of rules for how video and audio are transmitted over a network between a source, a server and a player. Different protocols are used for sending a live feed to a platform and for delivering video to viewers. - [Low-latency streaming](https://www.rentanott.com/glossary/low-latency-streaming) — Low-latency streaming is live streaming configured so that the delay between something happening in front of the camera and appearing on the viewer's screen is a few seconds, instead of the 10 to 30 seconds typical of standard internet streaming. ## Further reading - [Choosing a live streaming player](https://www.rentanott.com/blogs/live-streaming-player) - [Pricing](https://www.rentanott.com/pricing) - [Video bitrate calculator](https://www.rentanott.com/tools/video-bitrate-calculator) ## Frequently asked questions ### What does RTMP stand for? RTMP stands for Real-Time Messaging Protocol. ### Is RTMP still used? Yes, widely, for sending live streams from encoders to platforms. It is no longer used for playback in browsers. ### What is a stream key? A secret string that identifies and authorizes your stream at the platform's ingest address. Anyone who has it can stream to your channel, so keep it private. All 163 terms: [Streaming and OTT glossary](https://www.rentanott.com/glossary). ## Book a demo Tell RentAnOTT what you are launching. The team walks through the platform and maps the path to go-live around your catalog, markets and revenue model. Book a demo: https://www.rentanott.com/contact ## More from RentAnOTT - [Home](https://www.rentanott.com/index.md) — What RentAnOTT is, what every plan includes, and how launch works - [Features](https://www.rentanott.com/features.md) — Every core feature and optional add-on - [Pricing](https://www.rentanott.com/pricing.md) — Platform tiers, apps, add-ons, usage rates and example bills in INR and USD - [Free tools](https://www.rentanott.com/tools.md) — OTT app builder and calculators for streaming revenue, bandwidth, bitrate and pricing - [Insights](https://www.rentanott.com/blogs.md) — All streaming business articles - [Glossary](https://www.rentanott.com/glossary.md) — Definitions of streaming and OTT terms - [Book a demo](https://www.rentanott.com/contact.md) — Talk to RentAnOTT about your launch Full site in one file: https://www.rentanott.com/llms-full.txt