Free Chrome extensions
Three small fixes for the chores you repeat every day
Check a barcode number. Pull every tracking number out of a supplier's email. Fit a letter-size shipping label to 4x6 thermal paper. Each one does a single job, in your browser, for free.
- No ads
- No account
- Nothing leaves your browser
Barcode Checker
Is it a real barcode? Know before you list it.
A UPC with a wrong check digit, or one a spreadsheet stripped of its leading zero, gets a listing rejected or matched to the wrong product. Select the number on any page, right-click, and the checker tells you what it is and how to fix it.
- UPC-A, UPC-E, EAN-8, EAN-13, GTIN-14 and ISBN, by GS1's check-digit math
- Finds the dropped leading zero, the missing check digit and swapped digits
- Flags store-only numbers (prefix 2 or 04) that marketplaces reject
- Reads a whole pasted column and copies the results as CSV
Tracking Number Finder
Every tracking number in an email, with its carrier and link
Suppliers and 3PLs send tracking numbers buried in emails and portal pages, and someone copies them into the store or the books one at a time. Select the whole message, right-click, and get every number at once.
- UPS, USPS, FedEx, DHL, OnTrac, Canada Post, Royal Mail and Australia Post
- Checks the check digit, so a mistyped number is flagged before it reaches a customer
- Leaves out phone numbers, PO numbers and invoice numbers
- Copies the batch as CSV (number, carrier, link) or opens them all
4x6 Label Fitter
Letter-size label in, 4x6 thermal label out
Plenty of marketplaces and shipping sites hand you the label on a full letter page. A thermal printer wants just the label, upright and full size. Drop the PDF in and the fitter finds the label, turns it and sizes it to 4x6.
- Handles several files and pages at once, and pages turned sideways
- Optionally puts the packing slip on its own 4x6 page
- Drag on a page to draw your own crop when a layout is unusual
- Vector output, so barcodes print sharp at 203 or 300 dpi
Private by design
They can't see your pages, and Chrome enforces it
Seller tools often ask to "read and change all your data on all websites". These ask for almost nothing, and each one declares a content security policy that only lets it connect to its own files, so even a bug could not send your data anywhere.
| Extension | Permissions it asks for | What it can see | Can it connect anywhere? |
|---|---|---|---|
| Barcode Checker | One: the right-click menu | Only the text you select and choose to check | No. Only to its own files. |
| Tracking Number Finder | One: the right-click menu | Only the text you select and choose to search | No. Only to its own files. |
| 4x6 Label Fitter | None | Only the PDF files you drop onto it | No. Only to its own files. |
No accounts, no ads, no analytics inside the extensions. Read the privacy policy.
Questions
Are the extensions really free?
Yes. No account, no trial, no paid tier, and no ads. They are made by SKU.io, which sells inventory and order management software, and each one carries a single line saying so.
Can the extensions read the pages I visit?
No. None of them asks Chrome for access to any website. Barcode Checker and Tracking Number Finder only receive the text you select and then choose in the right-click menu. The 4x6 Label Fitter only reads the PDF files you drop onto it.
Does anything I check get sent to SKU.io?
No. Each extension declares a content security policy that lets it connect only to its own files, so Chrome blocks any request to SKU.io or anyone else. A carrier or marketplace page opens only when you click its link.
Do they work on Amazon Seller Central or the Shopify admin?
They never read those pages, by design. You can still select a code or a tracking number anywhere, including there, and right-click it, because Chrome hands the extension only the text you picked.
Which label PDFs does the 4x6 Label Fitter handle?
Any PDF with a shipping label on a letter or A4 page, including pages that are turned sideways and files with several labels. It finds the label, turns it upright and fits it to 4x6 inches. If a crop is wrong, drag on the page to draw your own.
These chores come from running several channels at once
SKU.io keeps inventory, orders and purchase orders for every channel in one place. See it on a call with the founder.
Book a DemoFounder-led demo · 2-day onboarding · no onboarding fees