Change tempo in 4 steps:
- Select the audio you want to speed up or slow down
- Go to Effect → Pitch and Tempo → Change Tempo
- Set target speed by percent, BPM, or final length
- Click Apply
What Is Tempo Change?
Tempo change modifies playback speed while keeping pitch constant. That means voices and instruments remain in the same key, just faster or slower. It is ideal for practice, transcription, and timing adjustments where pitch-shifting would sound unnatural.
Tempo change is perfect when you need speed changes without chipmunk or deepened voices. Slow a solo down to learn it note by note, or speed speech up to save listening time.
How to Change Tempo in Audacity
Step 1: Select Your Audio
Import your file and select the target region. For full-track edits, press Ctrl A ⌘A .
Step 2: Open Change Tempo
Open Effect > Pitch and Tempo > Change Tempo. This effect is designed specifically for speed changes that preserve pitch.
Step 3: Set Target Speed
Choose the control mode you prefer: percent change, BPM values, or exact output length. Audacity automatically links these fields, so changing one updates the others.
Step 4: Apply
Preview the result, then click Apply. For long projects, process in sections if you want to compare different settings quickly.
Change Tempo Settings Explained
Percent Change
Adjust speed as a percentage. -50% means half speed (double duration), while +100% means double speed (half duration).
Beats Per Minute (BPM)
Enter original and target BPM to match tracks musically. Audacity computes the required tempo shift automatically. This is useful for remixing and beat alignment.
Length (Seconds)
Set the exact output duration when fitting narration, ads, or cues to strict timing windows. Enter the desired "to" length and let Audacity solve the tempo change.
Use High Quality Stretching
Enable this for cleaner transients, especially on drums, piano, and rhythm-heavy material. It takes longer but improves quality for harder sources.
| Percent Change | Speed | New Length |
|---|---|---|
| -50% | 0.5x | 2x longer |
| -25% | 0.75x | 1.33x longer |
| 0% | 1x | Same length |
| +50% | 1.5x | 0.67x shorter |
| +100% | 2x | 0.5x shorter |
Common Use Cases
Where speed changing helps most:
- Practice music – Slow down technical passages and solos.
- Speech transcription – Reduce speed to catch every word.
- Podcast listening – Speed up content to 1.5x or 2x.
- Time fitting – Fit narration to ad slots and scene timing.
- BPM matching – Align tracks for DJ and editing workflows.
- Language learning – Slow native speech while preserving tone.
Tips for Best Results
- Keep changes moderate (within ±50%) for the most natural result.
- Enable high-quality stretching for percussion-rich material.
- For extreme slowdowns, use Paulstretch instead of standard tempo change.
- Always preview before applying to check for artifacts.
- For long audio, test on a short section first and then apply globally.
Frequently Asked Questions
Does Change Tempo affect pitch?
No. Change Tempo is
specifically designed to preserve pitch while changing speed.
What is the difference between Change Tempo and Change Speed?
Change Tempo keeps pitch unchanged. Change Speed changes both tempo
and pitch together.
How do I slow a song to half speed?
Set Percent Change
to -50%.
Can I speed a podcast to 1.5x?
Yes. Set Percent Change
to +50%.
How can I hit an exact final duration?
Use the Length
fields and enter the target "to" value.
Why does it sound distorted after large changes?
Very
large shifts can introduce artifacts. Use high-quality stretching and
smaller adjustments where possible.
Is there a hard maximum tempo change?
You can push
large values, but quality usually degrades as changes become extreme.
Can I preview speeds during playback?
Yes, the
playback speed control lets you audition timing without permanently
processing audio.
Download Audacity Free
Ready to speed up or slow down audio with precision? Download Audacity for free on Windows, macOS, and Linux.