Map diff

Where do two systems actually differ?

Pick two transliteration systems and inspect their rule sets side-by-side. Each row is one transformation rule, exactly as it appears in the JSON IR. The first 30 rules of each map are shown — enough to spot the divergences that matter.

System A

System B

bgnpcgn-rus-Cyrl-Latn-19470 rules (first 30)

iso-rus-Cyrl-Latn-9-19950 rules (first 30)

Why diff?

Choose with evidence.

Choosing between romanization systems is hard when the rules are buried in PDFs. The diff viewer surfaces the structural differences: which systems use parallel blocks, which add diacritics, which collapse distinctions.

Adoption decisions

Switching a newsroom or library from BGN/PCGN to ISO? See exactly what changes before you commit.

Map authoring

Writing a new map? Compare against an existing one to make sure you're not missing edge cases.

Linguistic research

Study how authorities have evolved their romanization conventions over time — pair an old system with a new one.