Font

Convert a font

Write a font in a different file format while keeping its characters. To keep only selected text, create a subset first.

Write a WOFF file

Place your source at fonts/Inter-Regular.ttf, create an output directory, and run this script beside vendor. Use a destination that does not exist.

<?php

require __DIR__.'/vendor/autoload.php';

use Alto\Font\Font;
use Alto\Font\Writer\WoffWriter;

$font = Font::fromFile(__DIR__.'/fonts/Inter-Regular.ttf');
$destination = __DIR__.'/output/inter.woff';

new WoffWriter()->write($font, $destination);

printf("Saved inter.woff (%d bytes)\n", filesize($destination));

You now have output/inter.woff, ready to reference from your application. WOFF compression is automatic. The original file is unchanged.

Running the script again with the same destination raises FontWriteException. Choose a new path, or explicitly manage replacement in your application. See writer failures for other writing failures.

Choose another output

Desired file Writer Additional requirement
Standalone TrueType (.ttf) SfntWriter None
WOFF (.woff) WoffWriter None beyond the required Zlib extension
WOFF2 (.woff2) Woff2Writer A configured Brotli compressor

Use the same load-and-write workflow with the selected writer. See Writers for TTF output and extracting a collection face, or Write WOFF2 for both Brotli options.

One loaded Inter face is written as TTF, WOFF and WOFF2, with the same characters and measured output sizes.

This fixture produces 66,912 bytes as TTF, 31,792 as WOFF, and 23,300 as WOFF2 with Brotli Maximum. No characters were removed. Other fonts and compression versions can produce different ratios. These measurements use the bundled Inter fixture.

What is preserved?

Conversion keeps the face's character and glyph data. Variable fonts retain their axes; choosing a weight with withVariations() does not make that view exportable as a static font.

Only supported TrueType outlines can be converted. Changing a file's extension does not convert CFF outlines into TrueType. See Formats. Webfont container metadata and private blocks are not preserved when rewriting. Details of reconstruction are in Writers.

Use dump() instead of write() when a storage API needs bytes rather than a local file. Both are described in the writer reference.

Conversion guides

  • Writers explains file output, byte output, collection extraction, and failure handling.
  • Compression compares SFNT, WOFF, and WOFF2 compression.
  • WOFF2 configures Brotli implementations and compression profiles.