目的が明確な人向けの回答

how to convert a jpg to pdf on iphone

The most direct native method: in the Files app, long-press any image file (JPEG, HEIC, PNG) and choose Quick Actions → Create PDF; the PDF appears in the same folder instantly, entirely on-device. Alternatively from Photos: tap Share → Print → pinch outward on the preview thumbnail to open a PDF view → tap Share again → Save to Files.

App StoreでScanTo Proを入手 → 無料ツール →

短い回答

The most direct native method: in the Files app, long-press any image file (JPEG, HEIC, PNG) and choose Quick Actions → Create PDF; the PDF appears in the same folder instantly, entirely on-device. Alternatively from Photos: tap Share → Print → pinch outward on the preview thumbnail to open a PDF view → tap Share again → Save to Files. Both methods are built into iOS, require no additional app, and produce a one-page PDF containing the image.

ScanTo Pro は iPhone だけでこれを実現します。きれいな PDF にスキャンし、端末上で OCR を実行、Face ID でファイルをロックすることも可能で、買い切り・サブスクリプションなしです。最新の機能は App Store の配信ページでご確認ください。

選ぶ前に確認すべきこと

  • Files app 'Quick Actions → Create PDF' is the fastest native method — one long-press, done
  • Photos app Share → Print → Pinch method also works and allows multi-image PDFs
  • Both methods are entirely on-device: the image data never leaves your iPhone
  • The resulting PDF embeds the image at approximately screen resolution (Print method) or original resolution (Quick Actions)
  • For batch conversion or custom page sizing, a dedicated app provides more control

実用的な選び方

  1. Files app 'Quick Actions → Create PDF' is the fastest native method — one long-press, done.
  2. Photos app Share → Print → Pinch method also works and allows multi-image PDFs.
  3. Both methods are entirely on-device: the image data never leaves your iPhone.
  4. The resulting PDF embeds the image at approximately screen resolution (Print method) or original resolution (Quick Actions).
  5. For batch conversion or custom page sizing, a dedicated app provides more control.

簡単比較

目的確認ポイント重要な理由
料金モデル便利な機能にサブスクリプション、買い切りアンロック、またはどちらも不要かを確認しましょう。初日に一番安いアプリが、1年後も一番安いとは限りません。
プライバシーモデル内容が機密性の高いものなら、端末上で処理できるものを優先しましょう。個人文書、履歴書、学習データ、家族のコンテンツは慎重に扱う必要があります。
エクスポート / ロックインファイル形式、共有、バックアップ、削除管理を確認しましょう。良いアプリは作業を閉じ込めるのではなく、完了を助けるべきです。

ScanTo Proが合う場面

サブスクリプションなしで、端末内で完結するプライベートなスキャンをしたいなら、ScanTo Pro がよく合います。

買い切り定期課金なし端末内処理

これはアプリ開発者が自ら作成した購入ガイドです。App Storeの機能や価格は変更される可能性があるため、購入前に製品ページで詳細をご確認ください。

よくある質問

Can I convert a HEIC photo (iPhone's default format) to PDF the same way?

Yes. The Files app Quick Actions → Create PDF and the Photos Print method both handle HEIC natively on-device, so you do not need to convert to JPEG first.

Does converting a photo to PDF affect its image quality?

The Quick Actions method in Files generally preserves the original image quality; the Print-to-PDF method re-renders at screen resolution (typically 72–150 effective DPI), which may reduce quality compared to the source photo.

Can I set a custom page size (A4, Letter) when converting a photo to PDF on iPhone natively?

The native iOS methods do not offer page-size selection — the PDF page is sized to the image dimensions. A third-party scanner or PDF app is required if you need an A4 or Letter-sized output.