Are these seller tools really 100% free?
Yes, every tool in this section is completely free with no subscriptions, no accounts, no credit cards, and no usage limits.
Ecommerce & Marketplace Hub100% Client-Side · Your files stay on your device
Free Tools for Online Sellers
Prepare product images, calculate prices and margins, create marketplace-ready listings and manage everyday ecommerce tasks directly in your browser.
No signup. Free to use. Zero per-user operating cost.
Optimized for:EtsyShopifyAmazoneBayTikTok ShopFacebook MarketplaceInstagramVintedOLXeMAGWooCommerce
Recommended Routine
Prepare a product listing
Follow this 6-step listing workflow to produce high-converting, compliant product listings across your storefronts.
1Visuals
Step 1: Prepare Photos
Resize, crop, frame, and export high-res marketplace images with correct aspect ratios.
2SEO
Step 2: Rename Files
Convert camera photos like IMG_8273.jpg into clean SEO-friendly filenames.
3Finance
Step 3: Calculate Pricing
Cover materials, labor, overhead, and platform fees to establish profitable selling prices.
4Copy
Step 4: Check Listing Title
Keep titles within character limits, avoid repeated words, and verify target keyword coverage.
5Keywords
Step 5: Organize Tags
Deduplicate keywords, remove punctuation issues, and format ready-to-paste tags.
6Conversion
Step 6: Create QR & WhatsApp Link
Generate direct customer order links and printable packaging QR codes.
All Free Seller Tools
Browse by category or search by task, marketplace, or feature.
Most Popular
Marketplace Image Prep
Batch resize, crop, frame with contain/cover, adjust backgrounds, watermark, and export ZIPs for Etsy, Shopify, Amazon, eBay, TikTok Shop, Vinted, OLX, and eMAG.
Batch upload10+ Marketplace presetsContain & Cover framing
Prepare product photos
SEO Utility
Product Image Renamer
Rename batch product photos into clean, sequential, SEO-friendly marketplace filenames with custom product slugs, SKUs, and numbering.
Batch filename previewSequential numberingSKU & separator options
Rename product images
Essential
Profit Calculator
Calculate true profit per item, gross and net margin percentages, markup, and break-even selling prices after product costs, packaging, shipping, ads, and marketplace fees.
EUR, USD, GBP, RON supportItemized cost breakdownGross & Net margins
Calculate profit margins
Makers & Sellers
Pricing Calculator
Determine what you should charge for your handmade or ecommerce products based on materials, labor hours, hourly rates, overhead, and desired profit margins.
Labor time & hourly rateOverhead allocationDesired margin solver
Calculate selling price
SEO Checker
Listing Title Checker
Check product listing titles against character limits for Etsy, Amazon, eBay, Shopify, and TikTok Shop. Spot repeated words, ALL CAPS, special characters, and keyword coverage.
Platform character presetsRepeated phrase detectorCaps & punctuation warnings
Check listing title
Fast Workflow
Tag & Keyword Organizer
Paste raw tags or keywords to remove duplicates, normalize casing, sort alphabetically or by length, detect near-duplicates, and format for Etsy (13 tags, 20 char limit) or general CSV.
Duplicate detectionEtsy 13-tag limit checkerNear-duplicate finder
Organize listing tags
Brand Protection
Watermark Tool
Add text or logo watermarks to multiple product photos right inside your browser. Control position, opacity, size, margin, and batch export clean ZIP files.
Text watermark with font stylesLogo/image uploadPosition presets & margins
Watermark photos
Shipping Utility
Volumetric Weight Calculator
Calculate dimensional (volumetric) weight vs actual scale weight for DHL, FedEx, UPS, DPD, GLS, and postal couriers in centimeters/kg or inches/lb to avoid surprise shipping surcharges.
Metric (cm/kg) & Imperial (in/lb)Standard courier divisors (5000, 4000, 6000, 139)Custom divisor support
Calculate billable weight
Direct Sales
WhatsApp Order Link
Generate instant wa.me order links and scannable QR codes with pre-filled product details, price, SKU, and customized order greeting for Facebook Marketplace, Instagram, and TikTok buyers.
Country code selectorPre-filled message templateInstant chat bubble preview
Generate WhatsApp link
Planning
Break-Even Calculator
Calculate exactly how many units you must sell and what monthly revenue you must generate to cover fixed costs, advertising spend, and platform transaction fees.
Fixed monthly expensesContribution margin per unitVisual break-even chart
Calculate break-even units
Sale Protection
Discount Calculator
Model Black Friday, seasonal promotions, and shop sales. See net profit after discounts and get immediate warning alerts if a promotion creates a negative margin.
Percentage or fixed discountCritical loss & zero-margin warningVolume increase needed formula
Calculate sale profit
Bundling
Bundle Calculator
Price product bundles, gift sets, and 'Buy 2 Get 1' offers for 2 to 10 items. Compare total cash profit and margin versus selling each product individually.
2 to 10 products per bundleIndividual price & cost trackingTotal customer savings
Calculate bundle price
Inventory
SKU Generator
Build clean, standardized stock keeping units (SKUs) by brand, category, product name, color, and size. Generate sequential batches and export to CSV.
Custom field buildersUpper / lower case formattingCustom separators
Generate SKUs
No AI · Pure Structure
Description Formatter
Structure raw descriptions into clear sections (Summary, Key Features, Dimensions, Materials, Care Instructions, Shipping) with bullet formatting, clean whitespace, and reusable templates.
Standard marketplace templatesOne-click bullet point conversionWhitespace & duplicate line cleaner
Format product description
Traffic Tracking
Seller UTM Builder
Build clean campaign tracking URLs with presets for Instagram Bio, TikTok, Pinterest, newsletters, and influencer collaborations without third-party tracking.
One-click platform presetsAutomatic URI encodingClean URL preview
Build campaign URL
Packaging Ready
Product QR Generator
Create high-resolution vector SVG and PNG QR codes for product packaging, instruction manuals, thank-you cards, WhatsApp ordering, and review request inserts.
Presets: Product, Shop, Review, WhatsAppCustom colors & quiet zoneHigh-res PNG & vector SVG export
Create product QR code
Amazon & eMAG Ready
Background & Canvas Tool
Center product photos on pure white (#FFFFFF) or custom solid color canvases, add margin padding, and crop to square marketplace-ready aspect ratios locally.
Pure white & solid color presetsPadding & breathing room sliderSquare 1:1, 4:5, 4:3 ratios
Add background canvas
Fee Transparency
Marketplace Fee Calculator
Compare transaction, payment processing, and listing fees across Etsy, eBay, Amazon, Shopify, TikTok Shop, or your own custom fee structure with verified formulas.
Verified baseline platform presetsCustom fee builderEffective fee % breakdown
Calculate marketplace fees
Frequently Asked Questions
Do you upload or store my product images and business data?
No. All image resizing, watermarking, background framing, and financial calculations run locally directly inside your browser. No product photos or private sales numbers are transmitted to our servers.
Which ecommerce platforms and marketplaces are supported?
Presets and workflows are tailored for Etsy, Shopify, Amazon, eBay, TikTok Shop, Facebook Marketplace, Instagram Shop, Vinted, OLX, and eMAG, plus custom stores.
Can I use these tools on mobile and tablet devices?
Yes. All seller tools feature responsive mobile-first layouts designed to work smoothly on phones, tablets, laptops, and wide desktop screens.
Cobalt Graphics Studio
Need a custom ecommerce solution?
Cobalt Graphics builds ecommerce websites, custom web applications and digital tools for businesses.