Tonga
What the source says
Referenced, awaiting primary-source reviewFormally adopted 4 November 1875. The red cross alludes to Christianity; white epitomizes purity; red evokes the sacrifice of the blood of Jesus Christ, which was shed during his crucifixion. Under Article 47 of the Constitution, the flag can "never be altered" and "shall always be the flag" of Tonga.
Referenced, not verified: a secondary work states this, and the document that constitutes the flag has not been read for this entry. What the marks mean.
Colors and meaning
Symbolism and history(r1)
A red field bears a white canton with a red cross, alluding to Christianity, adopted in 1875; under Article 47 of the Constitution the flag can never be altered and shall always be the flag of Tonga.
Most similar flags
The 6 closest of the 194 other national flags, ranked by a similarity index computed from the flag images themselves. The number is that index, 0–100 — not a claim that the two flags are “X% identical”.
Tunisia94near-identical colour proportions.
Switzerland93near-identical colour proportions.
Türkiye93near-identical colour proportions.
Morocco90near-identical colour proportions.
China89near-identical colour proportions.
Vietnam89near-identical colour proportions.
Computed at build time: each flag is rasterised to 64x48, and the score is 0.55 × colour overlap + 0.45 × structure. A different weighting would rank these differently. How the index works.
References — not verification
(r1) Referenced to Flag of Tonga (Wikipedia (English)) on 2026-07-17. States the adoption year, which colors the flag has, what the colors mean and the symbolism and history on this page. The passage it states them in is quoted at the top of this entry.
Further reading: Flag of Tonga on Wikipedia
