Importing large JSON dictionaries can cause the browser to freeze for several seconds. This is normal.

Format (copy-paste-able):
[
  {
    "r": "つるぎ",
    "s": [
      ""
    ],
    "l": [
      "line one of a definition",
      "line two of a definition",
      "etc",
      "last line of a definition"
    ]
  },
  {
    "r": "こだいしゅ",
    "s": [
      "古代種",
      "古代しゅ"
    ],
    "l": [
      "the ancients"
    ]
  }
]
Format (with comments, which break JSON parsing):
[
  { // entry one
    "r": "つるぎ",
    "s": [
      "" // entries with no "spellings" still have a single, blank spelling
    ], // comma
    "l": [
      "line one of a definition",
      "line two of a definition",
      "etc",
      "last line of a definition" // no comma
    ]
  }, // comma
  { // entry two
    "r": "こだいしゅ",
    "s": [
      "古代種",
      "古代しゅ" // no comma
    ], // comma
    "l": [
      "the ancients" // no comma
    ]
  } // last entry, so no comma
]