Free File Name Extractor & Duplicate Finder

If you save invoices, bills, or documents with the invoice number as the file name, it becomes very easy to accidentally save the same bill twice — especially when files come in from multiple sources, get forwarded over email, or are copied between folders during backups. When you're dealing with a handful of files this isn't a problem, but once a folder grows to a few hundred or a few thousand invoices, manually scrolling through the list to spot duplicates becomes slow, tiring, and genuinely error-prone. A single missed duplicate in an accounting folder can mean a bill gets counted twice, or worse, that a real invoice quietly gets skipped because it looks like "just another copy." This free tool solves that problem in seconds: it instantly reads the names of every file in a folder, lists them out in a clean, sortable table, automatically flags anything that looks like a duplicate, and lets you download the entire list — including a separate "Duplicates Only" sheet — as a ready-to-use Excel file.

How to Use the File Name Extractor

• Step 1 — Choose your files: Click "Select Entire Folder" to grab every file inside a folder in one click (the easiest option if all your invoices live in one place), or click "Select Files" if you'd rather manually pick specific files from different locations.
• Step 2 — Review the table: As soon as files are selected, the table instantly fills in with every file's name, extension, size, and last modified date. Any file that looks like a duplicate is automatically highlighted in red with a clear "Duplicate" tag, so you can spot problems at a glance without reading every row.
• Step 3 — Fine-tune the matching (optional): Use the "Smart match" and "Ignore extension" checkboxes above the table to control exactly how duplicates are detected, depending on how your files are named.
• Step 4 — Search if needed: For very large folders, use the search box to quickly filter the table down to a specific invoice number or partial file name.
• Step 5 — Export to Excel: Click "Download List as Excel" to get a complete spreadsheet of every file, plus a dedicated second sheet containing only the duplicates, grouped together for quick review and cleanup.

Smart Duplicate Matching

When you copy a file into a folder that already has one with the same name, most computers automatically rename the new copy rather than overwrite the original — for example, "1023.pdf" quietly becomes "1023 (1).pdf" or "1023 - Copy.pdf". Technically these are different file names, so a simple, literal name comparison would completely miss them and report both as unique. In practice, though, these almost always represent the exact same bill saved twice. Our "Smart match" option is built specifically to catch this — it automatically strips common auto-generated suffixes like "(1)", "(2)", "-copy", and "- Copy" before comparing file names, so these very common real-world duplicates still get flagged correctly. You can also toggle whether file extensions are considered during comparison, which is particularly useful if the same invoice was ever saved once as a PDF and once as a scanned JPG or PNG image — with extensions ignored, the tool will still recognize them as the same underlying bill.

Who This Tool Is Useful For

• Accountants and bookkeepers who store client invoices and bills as individual files named by invoice or bill number, and need a quick way to audit a folder for accidental duplicates before filing or reconciliation.
• Small business owners managing purchase orders, receipts, or scanned bills who want a simple sanity check before archiving a year's worth of documents.
• Office administrators cleaning up shared drives or downloaded email attachments, where the same document often ends up saved multiple times by different people.
• Anyone with a messy downloads or documents folder who wants a fast way to see exactly what's inside without opening each file individually.

100% Private, Browser-Based Processing

This tool never reads, opens, or uploads the actual content of your files anywhere. It only looks at metadata that your browser already has access to the moment you select a file — the name, the size, and the last modified date. None of this ever leaves your device or touches any server; the entire comparison and table-building process runs locally using JavaScript inside your browser tab. This makes the tool extremely fast, even with folders containing thousands of files, and means you can safely run it on folders containing sensitive financial documents, client invoices, or personal records without any privacy concerns.