| Aspect | Microformats2 | Microdata | JSON-LD |
|---|---|---|---|
| Markup | class and rel values | itemscope, itemprop | <script type="application/ld+json"> |
| Vocabulary | h-card, h-entry, ... | Usually schema.org | Usually schema.org |
| Nesting | Nested h-* roots | Nested itemscope | Plain JSON objects |
| Google rich results | Not a listed format | Supported | Supported, recommended |
Google calls JSON-LD, Microdata and RDFa "equally fine" but recommends JSON-LD: it is easy to maintain, nests cleanly and can be injected by JavaScript. Use it for search features (JSON-LD and schema.org), and add microformats for IndieWeb tools and rel="me"; both fit on one page.