Tempo mapping guides · Reaper
How to tempo map in Reaper.
Reaper imports tempo maps natively from MIDI files — no extensions needed. If you'd rather build the map inside Reaper by hand, the free SWS extension has a marker-based workflow. Here are both paths.
The built-in way
Tempo envelope and the SWS marker workflow.
Reaper's tempo map lives in the tempo envelope on the master track. Building one from a freely played recording is manual: mark the beats, then convert them into tempo changes.
- 01
Install the SWS extension
The marker-to-tempo workflow uses SWS/BR actions. Install SWS from sws-extension.org — it's free.
- 02
Remove existing markers and set the timebase
Delete any project markers first — leftover markers break the conversion. In Project Settings, set the timebase to Time.
- 03
Mark the beats
Play the recording and press M on each beat. Or record a click track and run "SWS/BR: Create project markers from notes in selected MIDI items".
- 04
Convert markers to tempo
Run "SWS/BR: Convert project markers to tempo markers" and enter the markers per bar (4 for 1/4-note beats). Enable "Create gradual tempo changes" for linear ramps.
The fast way
Import a MIDI tempo map instead.
If the tempo map already exists — for example, one exported from TempoSync — Reaper imports it natively, no SWS required.
- 01
Export the MIDI tempo map from TempoSync
The file contains the full tempo map and click events for the whole track.
- 02
Insert → Media file
Choose the MIDI file. Reaper asks whether to import the MIDI tempo map — tick the box.
- 03
Check the tempo envelope
The tempo changes land in the master track's tempo envelope, following your recording.
If the imported MIDI plays at Reaper's default tempo, the tempo changes weren't saved into the file — TempoSync's exports always include them.
The TempoSync workflow
From recording to tempo track.
1. Upload your recording — a live take, a drum recording, or anything recorded without a click.
2. Export the MIDI tempo map, along with a WAV click track if you want one.
3. Import the MIDI file using the steps above. Your tempo track follows the recording.
Comparison
Built-in tools vs TempoSync.
| Built-in | TempoSync | |
|---|---|---|
| Availability | Marker workflow needs the free SWS extension. | Native MIDI import — no extensions. |
| Effort | Tap or place markers beat by beat, then convert. | Automatic detection on upload. |
| Output | Tempo envelope in the current project. | Tempo map, WAV click track, and MIDI file for any DAW. |
| Learning curve | SWS actions are script-like and take practice. | Upload, export, import. |
FAQ
Tempo mapping, answered.
Do I need the SWS extension to import a MIDI tempo map?
No — Insert → Media file handles it natively. SWS is only for building tempo maps from markers by hand.
Why does the imported MIDI ignore its tempo?
Reaper only imports tempo when the prompt was ticked — or the file doesn't contain tempo events. TempoSync's export does.
The tempo map is right, but the audio moved.
Check the project timebase. With Time set for items, audio stays put while the tempo envelope changes.
What about ReaBeat?
ReaBeat is a free neural beat-detection extension for Reaper. It's Reaper-only; TempoSync runs the same kind of detection in the browser and exports a tempo map any DAW can use.
Skip the marker-by-marker workflow.
Upload the recording, export the MIDI tempo map, and insert it into Reaper. The tempo envelope writes itself.
No subscription. Audio is deleted after analysis.