1. 图片压缩 https://tinypng.com/
2. YAML, YML在线校验 https://old.qqe2.com/jsontool/yaml.php
3. 代码存储为图片 http://codezen.rishimohan.me/
4. 印记中文 https://docschina.org/
5. Diff https://www.diffchecker.com/