Flatten Multiple Excel Workbooks Into One Sheet for Pipeline Ingestion

When upstream stakeholders deliver data in separate Excel files instead of a database export, data engineers need a fast way to produce a single flat file without writing a one-off pandas script. Deliteful's Excel Merge tool handles column-union merging server-side and outputs a clean .xlsx ready for ingestion.

Data engineers regularly face ad-hoc Excel consolidation requests: finance sends five monthly export files, ops sends three regional breakdowns, and the ask is 'just get them into one table.' Writing a script for each variant is low-value work. A purpose-built merge tool that unions columns, preserves all rows, and outputs a flat .xlsx is faster for one-off jobs and removes a category of throwaway code.

Deliteful processes only the first worksheet from each uploaded file — a deliberate constraint that matches how most reporting exports are structured. Column alignment is automatic via union logic. Output is a single worksheet named 'Merged' with no formulas, no styles, and no merged cells, making it straightforward to read with pandas, openpyxl, or any ETL tool.

How it works

  1. 1

    Create a free account

    Google OAuth sign-in — no card, under a minute.

  2. 2

    Upload Excel source files

    Batch-upload all .xlsx or .xls files; the tool reads each file's first sheet.

  3. 3

    Auto-merge with column union

    All rows are combined into one sheet; missing columns get empty cells, no data is dropped.

  4. 4

    Download the flat file

    Get a clean .xlsx with no formulas — ready for pandas, Power Query, or your ETL pipeline.

Frequently asked questions

Does the output file contain formulas or formatting that could break a pandas read?
No. The merged output contains raw values only — no formulas, no merged cells, no cell styles. It reads cleanly with pd.read_excel() without additional cleanup.
How are column name conflicts handled across files?
Columns with the same name are treated as the same column — rows from that file populate that column. The tool does not deduplicate or rename columns, so inconsistent naming across files will produce multiple columns.
Is this useful for a one-time data migration where source data lives in Excel?
Yes. Upload all source files, download the merged sheet, and load it into your target system. It's faster than writing a script for a task you'll run once.
What if my data is on the second sheet, not the first?
The tool only processes the first worksheet of each file. Copy or move your data to sheet 1 before uploading.
Is there an API for this tool?
Not currently — Deliteful is a web-based tool. For repeated programmatic merges, a scripted solution may be more appropriate; this tool is best for one-off or infrequent consolidation tasks.

Create a free Deliteful account with Google and consolidate your ad-hoc Excel files into a pipeline-ready flat sheet without writing a script.