Which thumb do you use for the space bar in touch typing?

Use the thumb that feels more convenient, and use the same one for every space. In touch typing the thumbs rest on the space bar, and one of them presses it. The tutor advice we read leaves the choice to you, and no study we found compares the two thumbs for speed. The touch typing guide describes the thumbs as resting on the bar, and this page covers the choice of which one presses it.

Either thumb is acceptable, and the tutor rule is convenience

Ratatype, a typing tutor company, gives this instruction on its learning page: "Use the thumb of whichever hand is more convenient for you to press the Space bar." ¹ The rule names no preferred thumb. It asks you to pick the one that suits your hands, which means the choice is yours and the method does not depend on it.

We did not find one standard rule in the pages we read, so do not treat any single thumb as the required method.

The right thumb is the usual example in reference material

Wikipedia illustrates the home row with the word "poll" on a QWERTY keyboard, and its example puts the right thumb on the space bar ². The example shows where the thumb sits while the fingers work the home row, not which thumb a typist should prefer. It is a description of placement, so read it as one common picture, not a rule.

No study we found says which thumb is faster

Our search turned up tutor pages and community discussions about the space bar, but no controlled study that compares the thumbs. That means any preference rests on comfort and consistency, not on measured speed. We report that as a gap in the evidence, not as a finding that the thumbs make no difference.

Keep one thumb for the bar, because consistency is what predicts speed

The best evidence on finger use comes from the 2016 Aalto study. It found three predictors of high performance, and the first is that a letter is always pressed by the same finger ³. The study is about letters, not the space bar, so this is only our reading: a single thumb for every space may give the movement a settled pattern to repeat, and switching thumbs from word to word may break that pattern.

This is our reading of that study, not a finding about the space bar. It is the reason we suggest picking one thumb and keeping it.

What to do

1. Rest both thumbs lightly on the bar. The pressing thumb should not stray far from the bar, and the resting thumb can stay beside it.
2. Choose the thumb that feels more convenient. Ratatype's rule is to use the thumb of whichever hand is more convenient, so choose the one that feels natural to you.
3. Use the same thumb for every space for a practice period before you consider a change. Give the change a fair run before you judge it.
4. Keep the thumb on the bar between presses. Return it to rest after each space, as you return every finger to its home key.
5. Check accuracy, not only speed. A thumb that makes you miss spaces or type double spaces is not working, even if it feels fast. Count the mistakes in your practice text, using typing accuracy as the measure.

It depends on your hands and the keyboard

Keyboards differ in the width of the space bar, and that can change how a thumb feels when it presses. If pressing with one thumb causes pain or strain, stop and seek advice from a clinician. We cannot give individual medical advice, but a change of thumb or of posture is worth discussing if discomfort persists.

For the other fingers, read our question on finger placement. If you are learning the keys in order, the question on the number row covers the keys that come after the home row, and our question on whether you can touch type with one hand covers the method when only one hand is available. For how to choose a method at all, see our question on whether touch typing is worth learning. The full subject is in our overview of typing speed.