Base85 encoder and decoder for arbitrary data

Fund package maintenance!

2.0.0 2021-06-11 08:56 UTC

This package is auto-updated.

Last update: 2021-06-11 08:57:08 UTC


Latest Version Software License Build Status Coverage


Install with composer.

$ composer require tuupola/base85


This package has both pure PHP and GMP based encoders. By default encoder and decoder will use GMP functions if the extension is installed. If GMP is not available pure PHP encoder will be used instead.

$base85 = new Tuupola\Base85;

$encoded = $base85->encode(random_bytes(128));
$decoded = $base85->decode($encoded);

If you are encoding to and from integer use the implicit decodeInteger() and encodeInteger() methods.

$integer = $base85->encodeInteger(987654321); /* 3o4PT */
print $base85->decodeInteger("3o4PT", true); /* 987654321 */

Note that encoding a string and an integer will yield different results.

$string = $base85->encode("987654321"); /* 3B/rU2)I*E0` */
$integer = $base85->encodeInteger(987654321); /* 3o4PT */

Encoding modes

ASCII85 encoding. This is the default. 0x00000000 is compressed to z. Spaces are not compressed.

use Tuupola\Base85;

$ascii85 = new Base85([
    "characters" => Base85::ASCII85,
    "compress.spaces" => false,
    "compress.zeroes" => true

print $ascii85->encode("Hello world!"); /* 87cURD]j7BEbo80 */

Adobe ASCII85 encoding is same as previous except data is enclosed between <~ and ~>.

use Tuupola\Base85;

$adobe85 = new Base85([
    "characters" => Base85::ASCII85,
    "compress.spaces" => false,
    "compress.zeroes" => true,
    "prefix" => "<~",
    "suffix" => "~>"

print $adobe85->encode("Hello world!"); /* <~87cURD]j7BEbo80~> */

ZeroMQ (Z85) encoding. NOTE! Even though specification says input length must be divisible by 4, this is not currently enforced. Spaces and zeroes are not compressed.

use Tuupola\Base85;

$z85 = new Base85([
    "characters" => Base85::Z85,
    "compress.spaces" => false,
    "compress.zeroes" => false

print $z85->encode("Hello world!"); /* NM=qnZy<MXa+]NF */

Character set from RFC1924 which is an April fools joke. Spaces and zeroes are not compressed.

use Tuupola\Base85;

$rfc1924 = new Base85([
    "characters" => Base85::RFC1924,
    "compress.spaces" => false,
    "compress.zeroes" => false

print $rfc1924->encode("Hello world!"); /* NM&qnZy<MXa%^NF */


Install GMP if you can. It is much faster pure PHP encoder. Below benchmarks are for encoding random_bytes(128) data.

$ vendor/bin/phpbench run benchmarks/ --report=default

| subject         | mean            | diff     |
| benchGmpEncoder | 6,604.584ops/s  | +127.21% |
| benchPhpEncoder | 15,006.318ops/s | 0.00%    |

Static Proxy

If you prefer static syntax use the provided static proxy.

use Tuupola\Base85Proxy as Base85;

print Base85::encode("Hello world!") /* 87cURD]j7BEbo80 */

To change static proxy options set the Base85::$options variable.

use Tuupola\Base85;
use Tuupola\Base85Proxy as Z85;

Z85::$options = [
    "characters" => Base85::Z85,
    "compress.spaces" => false,
    "compress.zeroes" => false

print Z85::encode("Hello world!"); /* NM=qnZy<MXa+]NF */


You can run tests either manually or automatically on every code change. Automatic tests require entr to work.

$ make test
$ brew install entr
$ make watch


Please see CONTRIBUTING for details.


If you discover any security related issues, please email tuupola@appelsiini.net instead of using the issue tracker.


The MIT License (MIT). Please see License File for more information.