長度調整

html,
body,
svg {
  height: 100%;
}

<svg width="300" height="150" xmlns="http://www.w3.org/2000/svg">
  <g font-face="sans-serif">
    <text x="0" y="20" textLength="300" lengthAdjust="spacing">
      Stretched using spacing only.
    </text>
    <text x="0" y="50" textLength="300" lengthAdjust="spacingAndGlyphs">
      Stretched using spacing and glyphs.
    </text>
    <text x="0" y="80" textLength="100" lengthAdjust="spacing">
      Shrunk using spacing only.
    </text>
    <text x="0" y="110" textLength="100" lengthAdjust="spacingAndGlyphs">
      Shrunk using spacing and glyphs.
    </text>
  </g>
</svg>