How to increase podcast tempo for compact playback — free
- Step 1Export your finished episode — Bounce the final, edited episode to a file — most podcasts are
MP3, butWAV,M4A,FLAC,OGG, andOpusall work. Master it first (loudness, etc.) so the fast version inherits the finished sound. - Step 2Drop the episode into the tool — Drag the file onto the dropzone. The FFmpeg WebAssembly core loads in the tab; the episode stays in browser memory and is never uploaded.
- Step 3Set Tempo (%) to your target speed — For a 'fast' podcast version, enter 125 (1.25x) for a gentle bump or 150 (1.5x) for the common faster listen. The single control accepts 25–400; for spoken word, staying at or below 175 keeps it transparent.
- Step 4Run the conversion — Click run. FFmpeg applies
atempo = percent / 100and re-encodes once with libmp3lame (for an MP3 source). A typical episode finishes in seconds to a couple of minutes depending on length. - Step 5Download and label the fast version — Save the result (suffixed
-tempo). Name it clearly — e.g.episode-42-1.5x.mp3— so listeners know it is the compact version. Note the new runtime in the show notes. - Step 6Spot-check the start and an ad read — Listen to the cold open and a mid-roll. Speed-ups can make fast talkers harder to follow and can slightly distort music beds. If 150% sounds rushed, drop to 130%; if you want it tighter and it still reads cleanly, push toward 175%.
Podcast tempo → episode runtime
How each Tempo (%) compresses a spoken-word episode. Factor = percent / 100; new runtime = original / factor. Pitch is held constant so the host's voice is unchanged.
| Tempo (%) | Factor | 60:00 episode becomes | Listener feel |
|---|---|---|---|
| 110 | 1.10 | ~54:33 | Barely noticeable; trims dead air feel |
| 125 | 1.25 | 48:00 | Comfortable; most common faster listen |
| 135 | 1.35 | ~44:26 | Brisk but fully natural |
| 150 | 1.50 | 40:00 | Clearly fast, still intelligible |
| 175 | 1.75 | ~34:17 | Aggressive; fine for familiar hosts |
| 200 | 2.00 | 30:00 | Half time; some warble on fast speech |
What stays the same vs what changes
Tempo change re-times the episode but does not touch other properties. Master before you speed up.
| Property | Effect of tempo change | Note |
|---|---|---|
| Voice pitch / timbre | Unchanged | atempo locks pitch — no chipmunk effect |
| Runtime | Compressed by the factor | 150% → two-thirds the length |
| Loudness / true peak | Roughly preserved, can nudge peaks | Master first; limit after if it clips |
| Format | Preserved (MP3 → MP3) | libmp3lame default encode; no forced bitrate |
| ID3 tags / chapters | Not edited by this tool | Re-add chapters/tags after with id3-editor |
Tier limits for episode-length files
Tempo changer is Pro-tier. Episodes are often long, so the per-file duration cap matters as much as size.
| Tier | Max file size | Max duration / file | Access |
|---|---|---|---|
| Free | 50 MB | 30 min | Locked (needs Pro) |
| Pro | 200 MB | 120 min | Unlocked |
| Pro + Media | 100 GB | Unlimited | Unlocked |
| Developer | 100 GB | Unlimited | Unlocked |
Cookbook
Recipes for shipping a faster podcast version. Each shows the episode length, the Tempo (%) to enter, and the new runtime to put in your show notes.
Standard 1.25x compact version
The gentlest 'fast' version most shows publish. 125% trims a 48-minute episode to ~38:24 with the host's voice completely natural.
Input: ep-101.mp3 duration 48:00 Set: Tempo (%) = 125 Factor: 1.25 Output: ep-101-1.25x.mp3 duration ~38:24, same voice
Popular 1.5x version
150% is the classic 'fast' listen. A one-hour episode becomes exactly 40 minutes. Intelligible and clearly faster, still no pitch shift.
Input: ep-102.mp3 duration 1:00:00 Set: Tempo (%) = 150 Factor: 1.50 Output: ep-102-1.5x.mp3 duration 40:00
Brisk-but-natural 1.35x
If 1.5x feels slightly rushed for your hosts' cadence, 135% splits the difference — noticeably faster while staying relaxed.
Input: ep-103.mp3 duration 52:00 Set: Tempo (%) = 135 Factor: 1.35 Output: ep-103-1.35x.mp3 duration ~38:31
Trim only the dead-air feel (1.1x)
For a show with a deliberate slow pace, even 110% tightens the energy without anyone noticing it is sped up. Good for an A/B test.
Input: ep-104.mp3 duration 1:10:00 Set: Tempo (%) = 110 Factor: 1.10 Output: ep-104-1.1x.mp3 duration ~1:03:38
Master, speed up, then re-limit
Best-practice chain: master to your loudness target, speed up here, then run a limiter in case peaks crept up. Re-add ID3 tags last so the fast file is properly labelled in apps.
1. loudness-normalizer -> ep.mp3 at target LUFS 2. tempo-changer 150% -> ep-tempo.mp3 (40:00) 3. true-peak-limiter -1 dBTP if it clips 4. id3-editor: title 'Episode 105 (1.5x)'
Edge cases and what actually happens
Episode longer than your tier's duration cap
RejectedA 2.5-hour episode on Pro (120 min cap) is rejected before processing. Long-form shows should upgrade to Pro + Media (unlimited duration) or split the episode with audio-splitter, speed each part, and rejoin with audio-merger.
Free account tries to make a fast version
Requires ProThe tempo changer is minTier: pro, so free accounts cannot run it — the attempt is blocked as a tier limit. Podcasters need Pro or higher. Note the 30-minute free duration cap also would not fit most episodes.
Fast version clips on loud segments
Limit afterSpeeding up can nudge peaks higher. If the fast file clips on transients (laughter, stings), run it through true-peak-limiter at -1 dBTP. Master the normal-speed episode first so the fast one inherits clean levels.
Hosts sound rushed at 1.5x
Lower the percentCadence varies — fast talkers can become hard to follow at 150%. Drop to 130–135% for a faster-but-comfortable version. There is no rule that the fast cut must be exactly 1.5x.
Music bed warbles at high speed
Expectedatempo's time-stretching can add slight warble to sustained music beds above ~175%. For shows with prominent music, keep the fast version at or below 150% where the effect is negligible.
Chapters disappear in the fast file
Re-add metadataThis tool re-times audio; it does not preserve or rescale chapter markers and ID3 chapters. Re-create chapters/tags on the output with id3-editor, accounting for the compressed timestamps (a chapter at 30:00 in a 150% file is now at 20:00).
You expected a higher-pitched fast sound
By designatempo deliberately keeps pitch constant so the fast episode still sounds professional. There is no option to make it chipmunky here; if you want that creative effect, use pitch-shifter.
MP3 re-encode adds a generation of loss
One re-encodeThe fast version is a fresh MP3 encode of your episode — one extra lossy generation. Usually inaudible for spoken word at podcast bitrates. If you keep a WAV master, speeding that up and encoding to MP3 once at the end avoids stacking encodes.
Bitrate of the fast file looks different
Default encodeThe tool does not force a bitrate for tempo changes, so the MP3 output uses libmp3lame's default. If your feed needs a specific bitrate (e.g. 128 kbps mono spoken word), run the result through bitrate-changer.
Processing a long episode is slow
ExpectedA 90-minute episode decodes and re-encodes entirely in your browser, which takes real time proportional to length. The tab stays responsive — let the WebAssembly core finish rather than reloading.
Frequently asked questions
What speed should a 'fast' podcast version be?
125% (1.25x) for a gentle compact version, or 150% (1.5x) for the common faster listen. Both keep speech intelligible and the voice natural. If your hosts talk fast already, 130–135% is a safer ceiling than 150%.
Will the host sound like a chipmunk?
No. atempo speeds up time while keeping pitch constant, so the voice sounds the same — just faster. That is the key difference from a naive speed-up that shifts pitch.
How much shorter will my episode get?
New runtime = original / (percent / 100). So 125% cuts a 48-minute episode to ~38:24, and 150% turns a 60-minute episode into exactly 40 minutes. Put the new runtime in your show notes.
Is my episode uploaded to a server?
No. FFmpeg runs as WebAssembly in your browser and the file stays in memory. Unreleased episodes and ad cuts never leave your machine. Only an anonymous usage counter is logged if you are signed in.
Does it keep my episode as an MP3?
Yes — the output format matches your input, so an MP3 episode comes back as an MP3 (encoded with libmp3lame). If you bounced a WAV master, you get a WAV back; convert to MP3 afterward with wav-to-mp3.
Will the fast version keep my chapters and tags?
No. This tool re-times the audio only; it does not carry over ID3 tags or chapter markers, and chapter timestamps would be wrong anyway because the runtime shrinks. Re-add them on the output with id3-editor, recomputing timestamps for the new length.
Could the fast version clip?
Speeding up can nudge peaks slightly. Master at the normal speed first, then if the fast file clips, run true-peak-limiter at -1 dBTP. Tempo change does not normalise level on its own.
Can I process a two-hour episode?
Pro caps at 120 minutes and 200 MB per file. For longer episodes upgrade to Pro + Media (unlimited duration, up to 100 GB) or split with audio-splitter, speed the parts, and rejoin with audio-merger.
Do I need a paid plan to do this?
Yes. The tempo changer is a Pro-tier tool — free accounts cannot run it, and the free duration cap (30 min) would exclude most episodes regardless. Pro unlocks it with a 120-minute, 200 MB ceiling.
What bitrate will the fast MP3 be?
The tool does not force a bitrate for tempo changes, so it uses libmp3lame's default encode. If your distribution needs a specific bitrate, follow up with bitrate-changer.
Should I publish only the fast version or both?
Many shows publish the normal episode and offer the fast version as a bonus or in a separate feed. The tool just produces the file; how you distribute it is up to you. Label it clearly (e.g. '1.5x') so listeners pick deliberately.
Can I batch-produce fast versions of a back catalogue?
Pro allows up to 10 files per batch (Pro + Media up to 100). For automation, pair an @jadapps/runner and POST each episode plus { percent: 150 } to http://127.0.0.1:9789/v1/tools/tempo-changer/run — everything runs locally on your machine.
Privacy first
Every JAD Audio tool runs entirely in your browser via FFmpeg (WebAssembly) and RNNoise. Your audio files never leave your device — verified by zero outbound network requests during processing.