How to Use Flex Time in Logic Pro

Flex Time is Logic Pro’s tool for stretching and correcting the timing of audio regions without changing their pitch. If you want to learn how to use Flex Time in Logic Pro, the workflow is: turn on Flex for a track, choose the Flex algorithm that matches your material, then drag Flex Markers to nudge notes and beats into place.

This guide walks through enabling Flex, picking algorithms and fixing common timing problems. It applies to recent versions of Logic Pro, with the workflow described generally where menu locations vary by version.

Enabling Flex Time

Turn on the Flex view from the toolbar (the Flex button), then enable Flex on the track you want to edit. Logic analyses the audio and detects transients, marking them as the points you can grab and move. You’ll see a Flex algorithm chooser appear on the track header once Flex is active.

Choosing the right Flex Time algorithm

The algorithm controls how the audio is stretched, and matching it to the material keeps artefacts down:

• Monophonic — single-note lines such as bass, lead vocals or a solo instrument.
• Slicing — drums and percussion; it cuts at transients rather than stretching, preserving punch.
• Rhythmic — rhythmic but sustained material like rhythm guitar or keys.
• Polyphonic — chords and complex harmonic content; the most general-purpose for full pitched material.
• Speed (FX) — tape-style stretching that changes pitch with speed, useful as an effect.

Audition the result on the actual audio; the best choice usually reveals itself quickly.

Fixing timing with Flex Markers

Hover over a transient and click to place a Flex Marker, then drag it to move that beat or note earlier or later. The audio around it stretches to follow while neighbouring markers act as anchors. To tighten a sloppy performance fast, set the region’s groove and apply quantisation: with Flex active, the region’s Quantize setting snaps the detected transients to the grid, just like quantising MIDI.

Common Flex Time tasks

Align a doubled vocal to the lead by nudging its markers. Tighten a live drum take with Slicing mode and grid quantisation. Correct one late note in an otherwise good take by moving a single marker and leaving the rest untouched, which keeps the natural feel. This pairs well with comping vocals to first assemble the best take, then fix its timing.

Flex Time handles timing; its sibling Flex Pitch handles tuning. See how to use Flex Pitch in Logic Pro when notes are in time but out of tune. For the recording stage that comes first, our cross-DAW guide to time-stretching audio and the mixing and mastering hub add useful context.

Use it sparingly for the cleanest sound

Flex Time is best for correction, not transformation. Big timing moves stretch audio further and introduce artefacts, so capture a tight performance first and let Flex polish it. When you’re editing vocals, combine careful timing with the techniques in how to mix vocals for a professional result.

Frequently asked questions

Does Flex Time change the pitch of my audio?

No. Flex Time alters timing only and keeps pitch intact, except in Speed (FX) mode, which deliberately changes pitch with speed for a tape-style effect.

Why does my Flex edit sound glitchy?

Usually the wrong algorithm or excessive stretching. Match the algorithm to the material (Slicing for drums, Monophonic for single lines), and reduce how far you’re moving markers.

How is Flex Time different from Flex Pitch?

Flex Time corrects timing; Flex Pitch corrects tuning and lets you edit the pitch of individual notes. They’re separate Flex modes you choose per track depending on what you need to fix.