How it compares · tinyaml

	tinyaml	js-yaml 4	js-yaml 5	yaml	yamljs	@std/yaml
YAML 1.2 core schema	✅	✅	✅	✅	❌ `0o17` reads as 0	partial, `0o17` stays a string
Merge keys (`<<`)	✅ on by default	✅	✅ `mergeTag`	✅ `merge: true`	✅	✅
Custom tags	✅ `tags`	✅ `Type`, `Schema`	✅ `defineScalarTag`, `Schema`	✅ `customTags`	✅ `objectDecoder`	❌ in `parse`
Unknown tags	keeps the value	throws	throws	keeps the value	becomes `null`	throws
Anchors and aliases	✅	✅	✅	✅	✅	✅
Multiple documents	✅ `parseAll`	✅ `loadAll`	✅ `loadAll`	✅ `parseAllDocuments`	❌ merged into one	✅ `parseAll`
Error line and column	✅ 1-based	✅ 0-based `mark`	✅ 0-based `mark`	✅ `linePos`	partial, line only	✅
Dependencies	0	1, argparse	1, argparse	0	2, argparse and glob	0
ESM	✅ ESM only	✅ and CommonJS	✅ and CommonJS	✅ and CommonJS	❌ CommonJS only	✅ ESM only
TypeScript types	✅ built in	`@types/js-yaml`	✅ built in	✅ built in	`@types/yamljs`	✅ built in
Browser and edge	✅	✅	✅	✅	✅	✅
yaml-test-suite, valid	279 of 279	244 of 264	263 of 263	276 of 279	97 of 256	217 of 264
Size, gzip	7.8 KiB	14.4 KiB	17.1 KiB	29.9 KiB	8.8 KiB	11.3 KiB

The schema, merge, tag, document and error rows come from parsing the same inputs with each library's default options. A cell that names an option, like mergeTag or merge: true, needs that option. The others are defaults. The suite row is the first column of the correctness table, which leaves out cases refused for an unknown tag and, for yamljs, streams without exactly one document. yaml's size is parse and stringify only, and js-yaml 5's is load, loadAll, dump, Schema and YAMLException.