Why does TextMeshPro baseline jump vertically when text changes?

Auto Size recalculates the point size based on text length, and Vertical Alignment positions text relative to the bounds. When point size changes, glyph metrics change, shifting the baseline. Use Vertical Alignment Geometry Center or set Auto Size point range tight so size variations are smaller.

How do I keep TextMeshPro baseline stable across changes?

Set a fixed font size (disable Auto Size) and use Top vertical alignment so text grows downward predictably. If Auto Size must be on, narrow the Min/Max point range so resizes are subtle, and set AutoSizeIterations higher for smoother fits.

What is the difference between Baseline and Geometry Center alignment?

Baseline aligns based on the font's baseline metric. Geometry Center aligns based on the actual rendered geometry. Baseline keeps text consistent across font sizes; Geometry Center keeps it visually centered regardless of typography quirks. Choose per case.

Fix: Unity TextMeshPro Baseline Shifting After Resize

Quick answer: Auto Size + Baseline alignment causes visible vertical jumps when text changes. Disable Auto Size and use a fixed point size, or switch Vertical Alignment to Geometry Center so the rendered glyphs stay visually centered regardless of font metrics.

Here is how to fix Unity TextMeshPro labels whose vertical position appears to jump every time the text changes. A score counter, name plate, or chat bubble bobs up and down by a few pixels with each update. The cause is the interaction between Auto Size (which recomputes point size) and Baseline alignment (which positions based on font metrics that scale with point size).

The Symptom

A TMP label with Auto Size enabled and short fluctuating text (numbers, single words) jiggles vertically as text changes. Long text fills the box and sits low; short text in big size sits visibly higher.

What Causes This

Auto Size + Baseline. When text shrinks, Auto Size raises the point size, which raises the cap height and the ascender extent. With Baseline alignment, the visual top moves up.

Padding extents change. Padding around glyphs is proportional to font size. As size changes, padding shifts the bounds.

Mesh refresh on Set Text. Each text change rebuilds the mesh; small float jitter in the layout can produce visible position changes.

The Fix

Step 1: For stable labels, disable Auto Size. Pick a fixed point size that fits the longest expected text and use it always.

tmp.enableAutoSizing = false;
tmp.fontSize = 36;

Step 2: Use Geometry Center vertical alignment.

tmp.alignment = TextAlignmentOptions.Center;   // horizontal
tmp.verticalAlignment = VerticalAlignmentOptions.Geometry;

Geometry alignment uses the actual rendered glyphs’ bounds rather than the typographic baseline. Visually centered text stays centered regardless of point-size shifts.

Step 3: For Auto Size cases, narrow the range.

tmp.enableAutoSizing = true;
tmp.fontSizeMin = 28;
tmp.fontSizeMax = 36;
tmp.autoSizeTextContainer = false;

An 8-point range produces visible but minor vertical shifts. Wider ranges produce dramatic ones.

Step 4: Pin layout to a parent RectTransform. Place the TMP inside a fixed-size parent. Anchor the TMP to fill the parent. The parent does not move; the text stays inside.

Step 5: Disable Margin contribution. Margins cause additional padding. Set all four margin fields to 0 unless you need them; they add silent vertical offsets.

For Score Counters Specifically

Score counters are particularly noticeable. The fix combines:

Fixed font size (disable Auto Size)
Geometry center alignment
Tabular Figures (in TMP, set fontFeatures.Tnum = true) so numerals are equal-width and the box does not shift width with each digit

“Auto Size + Baseline = vertical bob. Fixed size + Geometry Center = stable label.”

Related Issues

For TMP emoji rendering, see TMP Emoji Sprite Asset. For TMP wrap issues, see TMP Text Not Showing.

Disable Auto Size. Geometry Center. Tabular figures. Counters stop bobbing.