#ethereum #icon #identicon #cryptography #blockies

no-std bin+lib eth-blockies

A pure Rust lightweight library/binary to get raw data of Ethereum-style blocky identicon, which can be used for generating blockies icon images, printing to terminal, etc

3 releases (stable)

1.1.0 Jul 2, 2023
1.0.0 Jun 28, 2022
0.9.2 May 10, 2022
0.9.1 Mar 21, 2022
0.9.0 Mar 21, 2022

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Used in pawprint

MIT license

1.5K SLoC



A lightweight library in pure Rust to get raw data of Ethereum-style blocky identicon, which can be used for generating blockies icon images, printing to terminal, etc.

Useful when getting raw RGB data of Ethereum-style blockies, as well as complete png image files.

Supports general Rust bin/lib, and WebAssembly (wasm) target.

Live Demo





  • Add a dependency to Cargo.toml of a Rust crate
    eth-blockies = "1.1"
    ...or without compressed_png default crate feature:
    eth-blockies = { version = "1.1", default-features = false }

Library Basic Usage

  1. Define a blockies type (size) to use

    use eth_blockies::{Blockies, BlockiesGenerator};
    // Blockies < size (const), T >
    type Icon<T> = Blockies<15, T>;
    • Cf) For Ethereum address blockies, EthBlockies is predefined as follows
    // use statement for Ethereum address blockies
    use eth_blockies::{EthBlockies, SeedInput, BlockiesGenerator};
    //   type 'EthBlockies<T>' is predefined as 'Blockies<8, T>'

  1. Select an input seed type

    • Check for SeedInput to get full list of input seed types
    // generate blockies from various input type
    let from_string = Icon::data("eth-blockies".to_string());
    let from_byte_vec = Icon::data(vec![0x0c, 0x93, 0xa3, 0x2e]);
    • Cf) For Ethereum address seeds, apply to_ethaddr_seed() before passing as input seed
    // generate Ethereum address blockies from various input type
    let seed_from_str = "0xe686c14FF9C11038F2B1c9aD617F2346CFB817dC"
    let from_str = EthBlockies::data(seed_from_str);
    let seed_from_bytes = [
          0xe6, 0x86, 0xc1, 0x4f, 0xf9, 0xc1, 0x10, 0x38, 0xf2, 0xb1,
          0xc9, 0xad, 0x61, 0x7f, 0x23, 0x46, 0xcf, 0xb8, 0x17, 0xdc,
    let from_bytes = EthBlockies::data(seed_from_bytes);

  1. Select an output data type

    // generate blockies in various forms
    let in_rgb_2d_arr = Icon::data("eth-blockies");
    let in_indexed_2d_arr = Icon::indexed_data("eth-blockies");
    let in_gray_2d_arr = Icon::data_mapped("eth-blockies", to_gray);
    let in_png_data_vec = Icon::png_data("eth-blockies", (128, 128));


  • Generate an Ethereum address blockies (with to_ethaddr_seed())

    use eth_blockies::{EthBlockies, SeedInput, BlockiesGenerator};
    let seed = "0xe686c14FF9C11038F2B1c9aD617F2346CFB817dC"
        .to_ethaddr_seed(); // required for Ethereum address blockies
    // 8x8 2D-array of (r, g, b)
        let eth_blockies_from_addr = EthBlockies::data(&seed);
    // uncompressed png data in byte vector
        let eth_blockies_png_from_addr =
            EthBlockies::png_data(&seed, (128, 128));
            // use below for compressed png
            // EthBlockies::compressed_png_data(&seed, (128, 128));
        // write data as png file
        use std::io::Write;
  • Generate an html img blockies element, on wasm target

    // addr to blockies data uri scheme,
    // which can be used directly in img elem 'src' or css 'url()'
    fn eth_blockies_data_uri(addr: &str) -> String {
       use eth_blockies::{EthBlockies, SeedInput, BlockiesGenerator};
       let addr_input = addr.to_ethaddr_seed();
       let output_dim = (128, 128);
       let data_uri_output = true;
          addr_input, output_dim, data_uri_output)
    use web_sys::*;
    let addr = "0xe686c14FF9C11038F2B1c9aD617F2346CFB817dC";
       .and_then(|w| w.document())
       .and_then(|doc| doc.body().zip(doc.create_element("img").ok()))
       .and_then(|(body, img)| {
          // create a new img html element with generated data_uri
          img.set_attribute("src", &eth_blockies_data_uri(addr))
             // then attach to body
             .and_then(|_| body.append_child(&img))

Cargo Features

  • compressed_png (Enabled by default)
    • This feature enables following functions:
    • This feature adds a following external dependency:
    • If png compression is not needed, disable this feature as follows when adding the crate:
      • E.g.
        • Shell: cargo add eth-blockies@1.1 --no-default-features
        • Cargo.toml: eth-blockies = { version = "1.1", default-features = false }



$ cargo install eth-blockies

Binary Usage

usage: eth-blockies <seed> [output-fmt (ansi|image)] [OPTIONS...]

<seed>                 Seed to generate blockies (e.g. Ethereum wallet address)

[output-fmt]  - ansi   (Default) Generate ansi sequence of blockies,
                       usually for printing to terminal
              - image  Generate png image data of blockies


        -e --ethseed   Interpret seed string as Ethereum address,
                       and canonicalize seed (to lowercase + set '0x' prefix)
                       to get Ethereum blockies correctly
        -a --ascii     (only for 'ansi' mode)   Get non-compact, big blockies
                                                with ascii (non-unicode)
        -r --raw       (only for 'image' mode)  Get uncompressed, raw png image

        -s --size=<BLOCKIES_SIZE>
                       Blockies size: # of elems per side (1-32) (Default: '8')

        -d --dimension=<WIDTH>x<HEIGHT>
                       Dimensions of output in the form of '(width)x(height)'
                       If not given, following is used (Default):
                       - ('ansi' mode)   '(blockies_size)x(blockies_size)'
                       - ('image' mode)  '128x128'

        -o --outfile=<FILENAME>
                       File name to write output
                       If the parameter is not given, stdout is used (Default)


- Outputs from following commands are all the same:
$ eth-blockies 0xe686c14ff9c11038f2b1c9ad617f2346cfb817dc
$ eth-blockies e686c14FF9C11038F2B1c9aD617F2346CFB817dC -e

- Outputs from following commands are all the same:
$ eth-blockies "generic_seed_not_ethaddr" --size=15
$ eth-blockies "generic_seed_not_ethaddr" ansi --size=15 --dimension=15x15
$ eth-blockies "generic_seed_not_ethaddr" a -s 15 -d 15x15

- Outputs from following commands are all the same:
$ eth-blockies "generic_seed" image > blockies.png
$ eth-blockies "generic_seed" i -d128x128 -oblockies.png
$ eth-blockies "generic_seed" i -d 128x128 -o blockies.png


Kim Hwiwon <kim.hwiwon@outlook.com>


The MIT License (MIT)