HEIC to PNG変換ツール — iPhone写真を劣化なしで変換

No — PNG is a lossless format, so there is no quality slider to tune; the tool always produces a bit-faithful decode of the HEIC pixels at full resolution. If you want a smaller file with an adjustable quality setting instead, use the HEIC to JPG converter, which exposes a 20–100% quality slider.

Switch the mode toggle from "Single file" to "Batch" above the upload area. Batch is a Premium feature: drop multiple HEIC/HEIF files, each is converted to PNG with the same lossless settings, and they're packaged into a single ZIP you download in one click.

This is expected, not a bug. HEIC uses heavy modern compression while PNG is lossless and keeps every pixel bit-exact, so file sizes typically grow 3–6x on the same photo. Choose PNG when you need pixel-perfect quality for editing or print; choose the HEIC to JPG tool if file size matters more.

For one or two photos, single-file mode gives an in-tool preview so you can review each result before downloading. For a whole camera roll or event folder, switch to Batch mode (Premium) — it applies the same lossless PNG conversion to every file and hands back one ZIP, which is far faster than converting file by file.

ブラウザは HEIC/HEIF 画像をネイティブにデコードできないため、JPG や PNG を扱うツールとは異なり、この変換ツールでは元の写真を画面に表示できません — 代わりにファイル名とアップロードアイコンが表示されます。ロスレスの PNG がサーバーから返ってくると（通常1秒未満）、それがプレビューとなり、ダウンロードもできます。つまり、表示できない元ファイルではなく、常に実際の出力をプレビューしていることになります。

Yes — once you're in Batch mode, each queued HEIC/HEIF file shows as a pill with its own small X button; click it to drop just that one file from the queue without touching the rest. If you want to start fresh, use the 'Clear all' button above the file list to empty the entire queue in one click, then drag in a new set of files.