Cipher tools: bringing the Japanese, Vietnamese and English pages up to parity

The cipher category is the largest single cluster of traffic on the site, but its non-Chinese pages turned out to be little more than the tool and an FAQ. Auditing section by section across all four languages found the gap was much wider than expected.

What was missing

Comparing each page's headings against the Chinese original, which is the source of truth:

• Japanese and Vietnamese had no section explaining how any of the eight ciphers works. Not just Atbash — all of them: Atbash, Rail Fence, Caesar, ROT13, Vigenère, Bacon, Morse, and Pigpen. A visitor landing on /ja/docs/crypto/rail-fence-cipher from search found a tool, three usage steps, and two FAQ entries. Nothing about what a rail fence cipher is. (ROT13 was the one partial exception, having a "common uses" list but no explanation.)
• The "Features" sections were Chinese-only. Rail Fence and Vigenère each have one in the Chinese version; no other language had them. (Caesar's Features section already existed in English.)
• English was missing four reference blocks: the Features sections for Rail Fence and Vigenère, the Bacon lookup table, and the Morse code chart. The Bacon table matters most — it is the thing you read to check what a code means, and it only existed in Chinese.
• Smaller English gaps: the Atbash page was missing the note about the mapping being symmetric, and ROT13 was missing the alphabet diagram showing the shift in both directions.
• All 32 pages set hide_table_of_contents: true, so even the Chinese pages gave you no anchor navigation.

The two non-Chinese languages with the most traffic were serving the thinnest pages. By visitor browser language over 22–28 September, English accounted for 182 visitors and Japanese for 71, against 264 for Chinese — so nearly half the audience was reaching these pages and finding almost nothing to read.

What changed

All eight cipher pages now have the same section structure in all four languages — two or three sections each, plus a fuller set of usage steps in Japanese and Vietnamese, which had been missing the "copy the result" step. Where a page has a worked example, the same example appears in every language, so the numbers on a Japanese page can be pasted into the tool and produce exactly what the page says.

Both reference tables — the 26-row Bacon cipher lookup and the 36-entry Morse chart — were rebuilt for each language and machine-verified against the source of truth in the tool code itself: every Bacon letter against BaconCipherTool.js, every Morse symbol against MORSE_MAP in MorseCodeTool.js. The Bacon table is 26 correct, duplicate-free entries in each of the four languages.

The in-page table of contents is now enabled across all 32 pages. With two or three sections per page the anchor navigation earns its place, and it gives crawlers a clearer read on the page structure.

No tool behaviour changed. This pass is content and navigation only.