StreamLive ProConnect vMix to StreamLive Pro and stream everywhere
Connect vMix to StreamLive Pro with a Custom RTMP Server destination: the fields, the quality settings to check, why one destination beats three, and the fixes.
vMix sends one stream to StreamLive Pro through a Custom RTMP Server destination, and StreamLive Pro sends it on to every network you ticked. You keep producing in vMix exactly as you do today; only the destination changes. This page covers the vMix side field by field. The short version, for OBS and vMix together, is Streaming from OBS or vMix with RTMP; if you are thinking of moving your production itself into the browser, read Coming from vMix? Feel at home.
Why not just use vMix's own destinations
vMix can stream to up to three providers at once: the 1, 2 and 3 buttons in its streaming window, available when FFMPEG is the application (vMix: Streaming settings). Each of those is a separate upload from your venue. Through StreamLive Pro you use one of them: the venue's line carries the stream once, and the copies to YouTube, a Facebook Page, Instagram, TikTok, X, LinkedIn, Twitch, Kick or a custom server are made on our servers. The number of destinations per broadcast depends on the plan (pricing page).
Before you start
- A paid plan. Encoder ingest is on the paid plans. In the 7-day trial the Encoder card shows "On paid plans" instead of an address.
- Channels connected under Connections. Instagram and TikTok need a fresh key for every live.
- vMix on Windows. vMix has no Mac version; on a Mac see the browser studio or vMix for Mac: does it exist, and what can a Mac user do in 2026?.
Steps
- Open the encoder panel in StreamLive Pro. Click New stream at the top of the dashboard and choose Stream from software like OBS (RTMP / SRT). The Live stream page opens on the Channels tab with the Encoder card.
- Copy the RTMP address and key. On the RTMP tab, click the copy button next to the URL, then the copy button next to the masked key. Do not reveal the key on a screen that is being recorded or shared.
- Open vMix's streaming window. In vMix, click the cog icon next to the Stream button (vMix: Getting started with streaming).
- Set the destination. In Destination choose Custom RTMP Server. Paste the address into URL and the key into Stream Key (vMix also calls it Stream Name).
- Choose the quality. Pick a Quality preset or click its cog. Check that Format is H264, that the encode size matches your production's shape, and that Keyframe Frequency is 2 seconds (vMix's default). Keep Application on FFMPEG.
- Tick your channels in StreamLive Pro. Switch on every destination in the Channels list and keep the page open and visible.
- Press Stream in vMix. Within about ten to thirty seconds StreamLive Pro says the stream was detected and you are live, shows your picture in the preview and sends the broadcast to the ticked channels.
- End the broadcast. Press Stop stream in StreamLive Pro to end it on every network, then stop streaming in vMix.
Quality settings that matter here
- Format H264, not HEVC or AV1. vMix offers all three. StreamLive Pro receives encoder streams through Cloudflare Stream, which accepts H.264 video and AAC audio only (Cloudflare Stream: Start a live stream, checked 5 November 2026). vMix's own help notes that AV1 and HEVC are "supported only by a few streaming providers" (vMix: Streaming quality).
- Bitrate. The default vMix preset is 360p at 1.5 Mbps, which is below the ingest's minimum of 2 Mbps combined and looks soft on YouTube. Raise it. For 1080p at 30 fps, YouTube lists 5 Mbps as the minimum (YouTube Help: live encoder settings); the ingest asks for under 14 Mbps, typically under 10. The reasoning per content type is in OBS settings for multistreaming to several networks, and it applies to vMix the same way.
- Keyframe Frequency 2. The ingest accepts 2 to 10 seconds; YouTube asks for 2 and no more than 4.
- Audio. AAC; 128 kbps is vMix's "near CD quality" value and YouTube's stereo value.
SRT from vMix
vMix sends SRT from Settings, Outputs, not from the streaming window. It has separate fields for Hostname, Port, Latency, Passphrase and Stream ID, and StreamLive Pro accepts the Caller mode. How to split our SRT address into those fields is in Stream with SRT from OBS, vMix or a hardware encoder.
What can go wrong
| Symptom | Fix |
|---|---|
| vMix shows an error and does not connect | The URL and key are swapped, or the key has a trailing space. Copy both again with the copy buttons. |
| vMix connects, StreamLive Pro stays offline | The key belongs to another broadcast. Copy the key from the card you have open now. |
| Connected but no picture | Format is HEVC or AV1, or the bitrate is under the ingest's minimum. Use H264 and a higher bitrate. |
| Stream works in the office but not at the venue | The venue blocks port 1935. Use the RTMPS tab address. |
| Live, but only some networks show it | Check the red cards in the channel list: an expired connection, or a used Instagram or TikTok key. |
More in My encoder says it is streaming, but there is no picture.
Frequently asked questions
Can vMix stream to several platforms through StreamLive Pro?
Yes. Set one Custom RTMP Server destination in vMix to the StreamLive Pro address and key. Our servers send the stream to every network you ticked, so your upload carries it once.
Where do I enter the StreamLive Pro key in vMix?
In the streaming window: Destination Custom RTMP Server, the address in URL and the key in Stream Key, also called Stream Name.
Which vMix quality preset should I use?
Not the default 360p preset. Choose H264 and a bitrate that suits your content and upload, for example 1080p at 4,500 to 6,000 kbps for a speaker, with Keyframe Frequency 2.
Can I use vMix during the trial?
No. Encoders, vMix included, are on the paid plans. The 7-day trial streams from the browser studio.
Is there a Mac version of vMix?
No, vMix runs on Windows only. On a Mac you can produce in the browser studio, which uses Preview, Program and Take in the same way.
Keep reading
A printable live stream checklist: test broadcasts, stream keys, sound check, backup internet, what to do if the stream drops, and the work after it ends.
Upload speed and bitrate for multistreamingYouTube's bitrate table for 720p to 4K, the upload you need to multistream from OBS vs a relay, CBR and 2-second keyframes, and how to test your connection.
RTMP vs RTMPS vs SRT: which one to use and whenRTMP vs RTMPS vs SRT compared: transport, ports, encryption, how each handles a bad line, which networks accept which, and how to choose for your encoder.
Stream with SRT from OBS, vMix or a hardware encoderStream to StreamLive Pro with SRT from OBS, vMix or a hardware encoder: the SRT address, passphrase, stream ID and latency, field by field, and when SRT helps.
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