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Inventory Management
Stay on top of your business with real-time inventory updates across all marketplaces. Manage your entire inventory from the Sidekick Tools app, with no spreadsheets and no guessing what is still available.
Crosslisting for resellers
The Best Cross Posting App for Resellers
List an item once and Sidekick Tools posts it to Poshmark, eBay, Mercari, Depop, Etsy, Grailed and Whatnot. Crosspost a closet to all seven marketplaces in under five minutes, which works out at roughly 30 seconds a listing.
No credit card required. Plans start at $9.99 a month. Cancel whenever you like.
4.6/5 on Trustpilot
7 marketplaces
iPhone, Android and web
Seven marketplaces
Sync Your Listings Across Seven Marketplaces
Connect each marketplace once. From then on your listings, edits and sales stay in step across all of them, with more marketplaces being added.
Poshmark
eBay
Mercari
Depop
Etsy
Grailed
WhatnotEach marketplace wants something slightly different, so you can tune the title, description and price per marketplace before you post. Grailed buyers search differently from Etsy buyers, and your listing can say so.
The basics
What Is a Cross Posting App?
A cross posting app, also called a crosslisting app or cross listing app, takes one listing and publishes it to several resale marketplaces at once. Instead of writing the same description seven times, you build the listing a single time and the app handles the copies.
The listing part is only half of it. The harder half is what happens after an item goes live in seven places. When it sells on Mercari, the copies on Poshmark, eBay and Depop are still live and still sellable. That is how resellers end up selling the same jacket twice and cancelling an order.
Sidekick Tools handles both halves. It crossposts the listing, then keeps the copies in step: when something sells, the duplicates come down automatically.
Without a cross posting app
Retype every title and description per marketplace. Reupload the photos. Keep a spreadsheet of what is listed where. Remember to pull the duplicates down by hand the moment something sells.
With Sidekick Tools
- Build the listing once and tick the marketplaces
- Sold items delist themselves everywhere else
- Stale listings relist on their own
- Every sale lands in one dashboard
Features
Sidekick Tools Cross Posting App Features
Everything here is included in the same subscription. There is no separate crosslisting add-on to buy.
Auto Delist and Relist
Say goodbye to duplicate listings and overselling headaches. Sold items disappear from the other marketplaces instantly, while unsold products get a second chance to shine at the top of the feed.
Automatic Auctions
Turn on the autopilot for your Poshmark Silent Shows. Sidekick Tools schedules, runs and tracks your auctions, monitoring views, bids and sales while you get on with sourcing.
Bulk Listing Editing Tools
Save hours with bulk listing editing. Update prices, tweak descriptions and optimize titles across many listings at once. The SmartFill feature makes mass edits quick, accurate and effortless.
Product Photo Editing Tools
Level up your listing photos without expensive gear. Remove photo backgrounds in seconds with the built-in editor, and create professional looking product shots with the AI Stock Photo Creator.
Sales Tracking
Track and analyze your sales across every marketplace from one app. From revenue to listing performance, Sidekick Tools gives you the clarity to see what is actually working and scale it.
How it works
Crosspost Your First Listing in Three Steps
Setup happens once. After that, crosslisting an item takes about 30 seconds.
Connect your marketplaces
Link Poshmark, eBay, Mercari, Depop, Etsy, Grailed and Whatnot to Sidekick Tools. You connect each one once and the connection stays active, so you never log in and out to list something.
Import or create the listing
Pull an existing listing in from any connected marketplace, or build a fresh one with your photos, title, description and price. Clean up the background and generate product shots right there if you want to.
Pick marketplaces and post
Tick the marketplaces you want, adjust anything that should read differently on a particular one, and crosspost. Sidekick Tools publishes to all of them and starts tracking the listing from that moment.
Why it matters
Why Resellers Crosspost in the First Place
More eyes per item
The same jacket sitting on one marketplace is seen by one audience. On seven, it is in front of seven. Nothing about the item changes, only how many people can find it.
Faster sell-through
Items that stall in one place often move quickly somewhere else. Grailed, Depop and Poshmark attract genuinely different buyers with different ideas of what something is worth.
Less dead inventory
Auto relisting pushes older stock back to the top of the feed instead of letting it sink, so the things you already paid for keep getting a chance to sell.
One place to run it
Listings, edits, sales and reports live in one app rather than seven tabs and a spreadsheet, which is usually what makes crossposting sustainable rather than exhausting.
What you get
Everything Included With Crosslisting
Crosslisting is one part of the app. These come with it rather than as paid extras.
| Capability | What it does | Included |
|---|---|---|
| Crossposting | Publish one listing to any of 7 connected marketplaces | Yes |
| Per-marketplace edits | Different title, description and price per marketplace | Yes |
| Auto delist | Pull the duplicates down automatically when an item sells | Yes |
| Auto relist | Refresh ageing listings so they return to the top of the feed | Yes |
| Bulk listing editor | Change prices, titles and descriptions in bulk with SmartFill | Yes |
| Inventory management | Real-time stock across every connected marketplace | Yes |
| Background remover | Strip photo backgrounds inside the app | Yes |
| AI Stock Photo Creator | Generate clean product shots without a studio | Yes |
| Automatic Auctions | Schedule, run and track Poshmark Silent Shows | Yes |
| Sales tracking | Revenue and listing performance across all marketplaces | Yes |
Comparison
How Sidekick Tools Compares to Other Crosslisting Apps
Feature by feature against the crosslisting apps resellers ask about most. These figures come from our own published comparisons and were correct when written, so check each provider for their current details.
| Feature | Sidekick Tools | Vendoo | Crosslist | Resell Kit | List Perfectly | PrimeLister |
|---|---|---|---|---|---|---|
| Supported Marketplaces | 7 | 11 | 9 | 6 | 10 | 8 |
| Mobile App for iOS & Android | Yes | Yes | No | No | No | Yes |
| Web Version | Yes | Yes | Yes | No | Yes | Yes |
| Listing Data Import | Yes | Yes | Yes | Yes | Yes (Not included in basic plan) | Yes |
| Bulk Listing Editing Tools | Yes | Yes | No | No | Yes (Not included in basic plan) | Yes |
| Inventory Management | Yes | Yes | Yes | Yes | Yes | Yes |
| Auto De-list of Sold Items | Yes | Yes | Yes | Yes | Yes (Only included in Pro Plus plan) | No |
| Relisting | Yes | Yes | Yes | Yes | Yes | Yes |
| Automatic Auctions | Yes | No | No | No | No | No |
| Sales Analytics & Reports | Yes | Yes | No | No | Yes (Not included in basic plan) | No |
| Product Photos Editing & Background Removal Tool | Yes | Yes | Yes | No | Yes | No |
| AI Stock Photo Creator | Yes | No | No | No | No | No |
| Live Chat Support | Yes | Yes | Yes | No | Yes | Yes |
| Community Support | Yes | No | No | No | No | No |
| Free Cross Posts | Yes | No | Yes | Yes | No | No |
Read the full breakdowns: vs Vendoo, vs Crosslist, vs Resell Kit, vs List Perfectly and vs PrimeLister.
Works on everything you already own
Sidekick Tools runs on iPhone, Android, Mac and Windows. The automations run in the cloud, so crosslisting, delisting and relisting keep going when your phone is closed or your laptop is shut.
There is nothing to install on your computer and no browser extension to keep updated. Sign in on the web app or use the mobile app, whichever suits where you are.
Pricing
Is There a Free Cross Posting App?
There are free crosslisting tools, and they tend to come with a catch: a hard cap on listings per month, a single marketplace connection, or no auto delist, which is the feature that actually prevents overselling.
Sidekick Tools runs a free 7-day trial with no credit card required, so you can crosslist real listings and see whether it fits how you sell before paying anything. After the trial, plans start at $9.99 a month and you can cancel whenever you want.
Safety
Is Crosslisting Allowed?
Yes. Listing the same item on more than one marketplace is a normal, long-standing part of reselling, and none of the seven marketplaces require you to sell exclusively with them.
The genuine risk in crossposting is not permission, it is overselling: an item sells in one place while the copies stay live everywhere else, and you end up cancelling on a buyer. Cancellations are what damage your ratings and your standing on a marketplace.
That is exactly what auto delist is for. When an item sells, Sidekick Tools takes the duplicates down for you, so the thing most likely to get a reseller in trouble is handled automatically rather than from memory.
Real reviews
What Resellers Say About Sidekick Tools
Real, unedited reviews from resellers on Trustpilot and Google Play, not stock quotes.
This app has boosted my sales by 50%. I have little to no problems crosslisting. It’s a great app!
It has made crosslisting a breeze. I love the charts, stats, sale notifications and everything about this app. Service when I have a problem is very fast, usually within 30 minutes.
Sidekick Tools has changed my reseller game. It’s made it so much easier to list items efficiently in much less time. Definitely doubled my profits monthly.
Stands head and shoulders above its supposed competition. I use it every day and am a huge fan. Plus, if there ever is a question they are extremely responsive. Love it!
I have had Sidekick for 4 weeks. This was my best month in a long time. I’m very happy using Sidekick. Customer service is great!
Love this app! My sales tripled and I love the silent auction option.
Read every review on Trustpilot.
Put Your Closet on Seven Marketplaces This Week
Start the free 7-day trial, connect your marketplaces and crosslist your first listing in about 30 seconds. No credit card, no commitment.
FAQ
Cross Posting App FAQs
Which marketplaces does Sidekick Tools support?
Sidekick Tools currently supports seven marketplaces: Poshmark, eBay, Etsy, Depop, Mercari, Whatnot and Grailed. More marketplaces are being added.
Can I edit or optimize my listings for each marketplace?
Yes. You can customize the title, description, price and other details per marketplace before you crosspost, so a listing can read the way buyers on that particular marketplace actually search.
What makes Sidekick Tools the best crosslisting app?
It covers seven major marketplaces, and the bulk editing tool lets you update many listings at once before crossposting them. Auto delisting and relisting are included rather than charged as extras, alongside automatic auctions, the AI Stock Photo Creator, the image background remover and sales reporting.
What happens when an item sells on one marketplace?
Auto delist removes the copies from your other connected marketplaces, so the item cannot be bought twice. This is the feature that prevents overselling, which is the main reason crosslisting goes wrong for resellers who do it manually.
Is crosslisting against marketplace rules?
No. None of the seven supported marketplaces require exclusivity, and selling the same item in more than one place is standard practice. What causes problems is leaving sold items live and then cancelling orders, which auto delist is designed to prevent.
How long does crosslisting one listing take?
Roughly 30 seconds per listing once your marketplaces are connected, which works out at a closet crossposted to all seven marketplaces in under five minutes.
Do I need to keep my phone or laptop open?
No. The automations run in the cloud, so crosslisting, delisting and relisting continue when your device is closed. You can check in from the mobile app or the web app whenever you want.
Can I import listings I already have?
Yes. You can pull existing listings in from a connected marketplace rather than rebuilding them, then crosslist those to the other marketplaces.
Is there a free trial, and do I need a card?
There is a free 7-day trial and it does not require a credit card. After the trial, plans start at $9.99 a month and you can cancel at any time.
Does it work on iPhone and Android?
Yes. Sidekick Tools is available on iPhone and Android, and there is a web app you can use from a Mac or Windows computer with nothing to install.
Can I bulk edit prices across marketplaces?
Yes. The bulk listing editor with SmartFill lets you update prices, titles and descriptions across many listings at once instead of opening them one at a time.
Does crossposting help items sell faster?
Each marketplace has its own audience, so an item that stalls in one place can move in another. Crossposting does not change the item, it changes how many buyers can find it. Auto relisting also keeps older stock visible instead of letting it sink down the feed.