CSV File Merger
Combine several CSV files into one, matching columns by header name.
- Free
- No signup
- Nothing uploaded
- No watermark
Drop files here
CSV files — add as many as you need · read on your device, never uploaded
How to Use the CSV File Merger Online
CSV File Merger stacks several CSV files into one. By default it matches columns by their header name, so a file whose columns are in a different order, or which gained a column last quarter, still lines up, and anything missing is left blank. Only one header row is written, not one per file. There is also a plain stack mode that trusts every file to have the same layout, which is faster and wrong if they do not.
Combines several CSVs into one, matching columns by header name rather than position. That matching is what makes it safe: concatenating files with columns in different orders is how data ends up in the wrong fields silently.
No software to install Free Works on any device
Step-by-Step Guide to Using the CSV File Merger
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1. Drop your files in, or click to choose them
Two or more.
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2. Drag them into the order you want, and set how they should be joined
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3. Press Merge, then download the single file that comes out
No .csv file to hand? Download a sample CSV file (635 B) and try it.
What is the CSV File Merger?
Combines several CSVs into one, matching columns by header name rather than position. That matching is what makes it safe: concatenating files with columns in different orders is how data ends up in the wrong fields silently.
CSV files
.CSV .TSV .TXTCombine several CSV files into one, matching columns by header name.
At a glance
- Takes: Two or more .csv, .tsv or .txt files
- Matching: By header name (default) or by position
- Missing columns: Left blank for files that lack them
- Header: Written once at the top of the merged file
- Gives: One CSV to download
- Runs: In the tab; files stay on your computer
Why Inspect a Document Before Sending?
A file can look fine on screen and still fail a portal check because of its version, page size, fonts or hidden permissions. Inspecting it first shows those details plainly, and the helper tools split, merge and shrink data and office files.
“Check the file before someone else rejects it.”
- Page count and size at a glance
- Version and standard checks
- Hidden attachments brought out
- Data files split or merged
- Fonts and links listed
- Permissions shown before you share
- Office files made smaller
- Excel formulas explained
Popular Uses for Document Checkers
These checks answer the questions people have about a file before it goes anywhere.
- Print shop checks Confirm page sizes, orientation and PDF/X before sending artwork to a printer.
- Archive submissions Check whether a PDF meets PDF/A before submitting it to a court or registry.
- Counting pages and words Find the page count and word count of a PDF for a quote or limit.
- Checking links List every link inside a PDF to find broken or outdated addresses.
- Font problems See which fonts a PDF uses and whether they are embedded for printing.
- Shrinking Office files Make a heavy Word, Excel or PowerPoint file smaller before emailing it.
- Splitting large CSVs Cut a huge CSV or JSON file into parts that other tools can open.
- Excel formula help Check a formula for errors or turn a column number into its letter.
What You Can Do with the CSV File Merger
Accepts CSV, TSV, TXT
Understands CSV structure rather than treating the file as bytes
Splits on record boundaries rather than byte counts, so no row or object is cut in half
Preserves the original encoding and line endings instead of normalising them silently
Why Use ToolXkit for CSV File Merger?
Your files stay with you
Everything runs inside your browser. Nothing you open or type is uploaded to a server.
Free, with no catch
No signup, no watermark and no daily limit on how often you use it.
Fast
Results appear in seconds, because nothing has to travel over the internet and back.
Works on any device
Use it on a computer, tablet or phone, in Chrome, Edge, Firefox or Safari.
Nothing to install
No app, no extension and no desktop program. Open the page and start.
Made for real people
Plain words and clear buttons, built by one developer who wanted tools like this to exist.
Document Inspection for Different Users
Printers and publishers
Check PDF/X, page sizes and fonts before a job goes to press.
Legal professionals
Confirm PDF/A compliance, page counts and permissions before filing documents on a court portal.
Translators
Count words in a PDF to quote a fair price for a translation.
Data analysts
Split, merge and count rows in CSV and JSON files too big to open.
Office administrators
Check file sizes, versions and security settings before uploading to portals.
Web teams
Extract links and bookmarks from PDFs before publishing them on a website.
Best Times to Check a PDF or Data File
Inspection tools are worth a look when you are:
- Sending artwork to a printer
- Filing papers on a court portal
- Quoting a translation job
- Opening a CSV too big for Excel
- Checking why a PDF was rejected
- Sharing a file with restrictions
- Emailing a heavy PowerPoint deck
- Auditing links in a brochure
Tips and Good to Know
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Matching is on exact header text. Email and E-mail are two columns; rename them with CSV Column Renamer first.
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It appends rows; it does not join on a key. To combine customer details with their orders, you need a lookup, not a merge.
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Duplicate rows across files are kept. Run CSV Row Counter on the result to see how many.
Frequently Asked Questions
Answers to common questions about this tool.
Do I need to install anything to use the CSV File Merger?
No. CSV File Merger runs entirely in your browser — there is nothing to download, no extension and no desktop program. It works the same on Windows, macOS, Linux, Android and iPhone.
Is it safe to use the CSV File Merger online?
Safer than the usual alternative, yes. Most online tools upload your file to a server you know nothing about, where it sits until someone deletes it. Here the file never leaves your device — the processing happens in the page itself, so there is no server copy to leak, retain or sell.
Does CSV File Merger change my file?
The inspection tools only read the file and report what they find, so your document is untouched. Tools that split, merge or compress give you a new file and leave the original as it was.
What is PDF/A and do I need it?
PDF/A is a version of PDF made for keeping documents readable for many years. Some courts, government offices and archives ask for it. If a portal does not mention it, an ordinary PDF is fine.
Can I use CSV File Merger without signing up?
Yes. No account, no email and no fee. Drop in the file and the report or result appears on the page, ready to read or download.
Why was my PDF rejected by a portal?
Common reasons are a file that is too large, the wrong PDF version, a password, missing fonts or pages of the wrong size. Checking those details here usually points to the cause.
Further reading
- PDF/A Family (Library of Congress) The Library of Congress overview of PDF/A, the version of PDF made for long-term keeping.
- PDF/X (Wikipedia) What the PDF/X standards require so a file prints the same at any press.
More Document Inspector Tools
Other free tools for the same kind of job.
- Compress EPUB A smaller .epub — pictures re-encoded, text and chapters untouched, on your device. Open tool
- Compress Excel Workbook Shrink a workbook to a size you choose. Open tool
- Compress Office Document Shrink Word, PowerPoint, Excel or EPUB files in your browser. Open tool
- Compress PowerPoint Shrink a deck to a size you choose. Open tool
- Compress Word Document Shrink a Word file to a size you choose. Open tool
- CSV Column Merger Join two or more CSV columns into one, with your own separator. Open tool
- CSV Column Renamer Rename the headers in a CSV without touching the data underneath. Open tool
- CSV Column Reorderer Move CSV columns into a different order, or drop the ones you do not need. Open tool
- CSV Column Splitter Split one CSV column into several on a comma, space or any separator. Open tool