Excel ファイルを結合

月次レポートの集約 — 12 か月分の月次レポートを 1 つの年間ブックにまとめ、各ファイルを 1 シートとして保持します。

拠点からの収集 — 各オフィスが同じテンプレートを送ってくる場合、結合して結果を並べて比較できます。

アーカイブ — 多数の小さな添付ファイルを残す代わりに、関連するブックを 1 つのファイルにまとめます。

Merging is easy to confuse with a few related jobs, so pick the right tool before you upload:

• Merge Excel files (this page) — combines several workbooks into one workbook where every original sheet stays its own tab. Nothing is stacked or joined: a sheet named January in file A remains a separate sheet next to a sheet named January in file B, renamed automatically if the names collide.
• Merge sheets into one — the opposite direction: it takes the many sheets inside a single workbook and stacks them vertically into one flat table, aligning headers and optionally adding a source-sheet column.
• Join Excel tables — a database-style left join that enriches one table with columns looked up from another table by a shared key column, instead of collecting whole sheets.
• Compare Excel files — highlights the cells that differ between two versions of a workbook rather than combining them.
• Remove duplicates from Excel — merged archives often contain repeated rows; this tool deduplicates a sheet by the columns you choose.

Everything runs locally in your browser. The files are parsed in memory, combined into a new workbook structure, and written back as a single .xlsx download — nothing is uploaded to a server. That makes the tool suitable for payroll exports, financial statements, or client data that should never leave your machine.

Sheets keep their original names whenever possible. When two incoming files contain a sheet with the same name, the later one is prefixed with its file name so you can still tell them apart. Internal metadata sheets created by the editor are skipped automatically. Cell values, dates, and number formats survive the merge; highly specific styling such as conditional formatting rules may be simplified in the output.