Your show files,
mirrored in real time.

What ShowSync does

ShowSync runs quietly in the menu bar and mirrors a folder from one Mac (the Main) to another (the Backup) over your local network. It is built for live production, where a second copy of your cues, sets, recordings, or project files can save a show.

Requirements

• Two Macs running macOS 13 (Ventura) or later — one acts as Main, one as Backup. Both should run the same version of ShowSync.
• Both Macs on the same local network (wired is recommended for shows).
• Local Network access allowed for ShowSync on both Macs — macOS asks the first time (see First launch & permissions).
• For the Backup's folder, the Mac's internal drive or a USB 3 or faster external drive. Network drives and file shares are not supported.
• An internet connection at first run to start a trial or activate a license. After activation, ShowSync verifies your license offline — no internet needed at show time.

First launch & permissions

The first time ShowSync runs, macOS asks whether it may use your local network — ShowSync explains: "ShowSync uses your local network to find your Backup Mac and copy show files to it." Click Allow on both Macs. Without it, the two Macs can't find or reach each other.

macOS may also ask for access when you choose a folder on the Desktop, in Documents or Downloads, or on an external drive. Allow it, so ShowSync can use the folder you picked.

If Local Network access is blocked, ShowSync says so in the popover: "If the Backup is on and on this network, macOS may be blocking local network access for ShowSync." Click Open Privacy Settings and turn ShowSync on under Local Network. "If it's already allowed, switch it off and on again, then quit and reopen ShowSync."

Quick start

If you just want to get running, this is the short path. Each step is expanded later in the guide.

1. Install ShowSync on both Macs. It appears in the menu bar — click the icon to open it. Click Allow when macOS asks about your local network.
2. On the Backup Mac, set its role to Backup (Settings → Connection → Role → Switch to Backup).
3. On the Main Mac, start a trial or activate a license (Settings → License). Until then, the Main Mac runs in free Backup-only mode.
4. Pair the two Macs. On the Main Mac, select the Backup in the list under Settings → Connection, then click Pair Automatically (Settings → Identity & Trust). Confirm the matching code on the Backup.
5. Choose your source folder on the Main Mac (Choose…).
6. Click Sync Now. Your files mirror to ~/Sync on the Backup.

Upgrading from version 1

If you used ShowSync version 1, install the new version on both Macs. Here's what to expect:

• Your settings and license carry over — source folder, Backup, Auto Sync and Push Sync, Verify mode, shortcut, Version History and the rest.
• Pair the two Macs again. The old pairing isn't used by this version — see Pairing the two Macs.
• Files already on the Backup are kept. On the first sync the Backup checks the show files it already holds and only receives what's missing or different. You'll see Checking files already here… on the Backup while it reads them — on a large show or a slow drive this can take a while, once.
• Both Macs should run the same version. A new Main can't pair with a Backup still on version 1.
• Going back to version 1 isn't supported once the new version has saved its settings.

Main & Backup roles

Every Mac running ShowSync is either a Main or a Backup.

To change a Mac's role, open Settings → Connection → Role and click Switch to Backup or Switch to Main. You'll be asked to confirm — "The app will restart in the new role."

Prepare the Backup Mac

The Backup Mac receives files. It only needs ShowSync running with its role set to Backup — there's nothing else to turn on in System Settings beyond allowing Local Network access.

1. Set the role to Backup. Settings → Connection → Role → Switch to Backup. The app restarts as a Backup.
2. Allow Local Network access if macOS asks (see First launch & permissions).
3. Confirm it's ready. The Backup popover shows Ready, Last received, the folder files arrive in, and Storage. Open Connection Info to see Network Discovery and This Mac's IP. When files arrive you'll see Receiving….

Pairing the two Macs

Pairing establishes a trusted, encrypted connection between Main and Backup. It only has to be done once per pair.

Automatic pairing (recommended)

1. On the Main Mac, open Settings → Connection. Leave Discovery on Automatic.
2. Your Backup Mac appears in the list of Backups. Select it, then open Identity & Trust and click Pair Automatically.
3. ShowSync shows Pairing…, then a request appears on the Backup Mac titled "Pairing Request".
4. On the Backup, check the verification code matches the one under "This Mac's Verification Code" on the Main, then click Trust. If nobody answers, the request closes by itself after about two minutes.
5. The Main shows Paired with [name] and the Secure Connection indicator turns to Connected.

Manual setup

If the Backup doesn't appear in the list, pair by hand with an address and a one-time key:

1. On the Main Mac, open Settings → Identity & Trust → Pairing and click Set Up Manually (it reads Set Up Secure Connection when no Backup has been found).
2. The Main shows a Set Up Manually box with an Address and a Key. Use Copy Key and Copy Address if you want to paste them somewhere, and keep the Main on the same network. Done closes the box — the Main keeps waiting for the Backup.
3. On the Backup Mac, open Settings → Identity & Trust → Pairing and click Set Up Manually. Type the Address and the Key exactly as shown on the Main, then click Join.
4. The Backup confirms "Secure Connection Established — This Mac is now paired and ready to receive backups." If it says "Could Not Connect — Check the address and key and try again.", click Retry and re-type them.

If you use Discovery Manual, also enter the Backup's IP on the Main under Settings → Connection → Destination → Backup IP (Edit, then Save). The Backup's IP is shown in its Connection Info.

If you ever need to unpair

In Settings, Forget This Backup (on the Main) or Forget Paired Main (on the Backup) clears the pairing. You'll be asked to confirm. To re-pair, pair again as above.

Choosing folders

On the Main — the source

Under Settings → Connection → Source, click Choose… and pick the folder you want mirrored (your show folder, project, recordings, etc.). Until a source is set, ShowSync shows "Choose a source folder." If the folder is later moved or renamed, Connection Info marks it Missing.

On the Backup — the destination

Files arrive in ~/Sync by default. To use a different location, open Settings → Connection → Destination on the Backup and click Change.

Keeping room on the Backup

Minimum Free Space (Settings → Connection on the Backup, default 2 GB, adjustable from 1 to 99 GB): "Sync is refused if the drive has less than this free." Before each sync ShowSync also checks the Backup has room for the files about to arrive, and refuses up front — with a message saying how much space to free — rather than failing part-way.

If the Backup's drive goes missing

The switch "If my backup drive is unavailable, back up to my home folder instead" is off by default. Off, a sync stops with a clear warning when the folder can't be written. On, files go to your home ~/Sync folder while the drive is away and back to the drive the moment it returns; the Backup popover shows "Backup drive unavailable — backing up to your home Sync folder" while that's happening.

Save disk space

Save disk space is on by default: "Keeps the Backup close to the size of the show: changed files are sent whole and the hidden block store is emptied after each sync." Leave it on unless you have a reason not to.

Choosing the network

ShowSync can be locked to one network connection. Open Settings → Connection → Network Interface on each Mac: "Locks ShowSync to one network connection: discovery, pairing, and backups all use only this interface. Automatic picks the first available."

• Automatic (first available) — the default. The menu shows which adapter it picked, for example Automatic – Ethernet.
• A named adapter — Ethernet, Wi-Fi, Thunderbolt Bridge and so on, using macOS's own names. A Thunderbolt cable is treated like any other adapter.

Syncing files

Open the Main Mac's popover and click Sync Now. ShowSync copies any new or changed files to the Backup. The first sync sends everything; after that, unchanged files are skipped and only new or changed files are sent — a changed file is sent again in full.

The status first reads Checking for changes…, then shows progress like Syncing… 64% · 2.1 GB of 3.3 GB. You can stop it with Cancel Sync. When it finishes you'll see ✓ Synced, and Last sync updates with the time, the number of files sent, and the size. "Synced" means the files are written to the Backup's drive, not just received.

As files arrive, the Backup checks each piece against its fingerprint, and checks again before it resumes an interrupted transfer. To confirm the whole Backup afterwards, use Verify.

A sync never deletes anything on the Backup. If a sync can't run — not enough space, the Backup's folder can't be written, or the show folder is too big for one sync — ShowSync refuses before sending anything and says why.

Retry & resume

Show networks get bumped. If a sync is interrupted — a cable pulled for a moment, a brief network drop — ShowSync handles it for you. There's no setting; it's always on.

Automatic retry

ShowSync waits for the Backup to answer and tries again — up to 2 automatic attempts, within 3 minutes of the interruption. While it does, the status reads Sync interrupted. Retrying (1 of 2)…. Cancel Sync stops it at once.

Resume

An interrupted transfer carries on from where it stopped: the Backup keeps what it already received, and only what's still missing is sent. Anything kept from the interrupted transfer is checked again before it's used.

If it still can't finish

Once the attempts are used up, the sync shows Failed with the reason — for example "Sync interrupted — files may be incomplete" or "Couldn't reach the Backup — nothing was sent." Fix the connection and click Sync Now; it picks up where it left off.

Auto Sync & Push Sync

Two options in Settings → Behaviour keep the Backup current without you clicking each time:

Auto Sync

Mirrors on a schedule. Pick from preset intervals — 30 seconds, 5, 10, 15, or 30 minutes, or 1 hour — or set a custom interval of 1–360 minutes and click Apply. A · Auto badge appears in the popover when it's on, and Next auto sync counts down. If the Mac slept through a scheduled sync, it runs once shortly after it wakes.

Push Sync

Mirrors automatically whenever files in the source folder change. ShowSync watches the folder and, once changes settle (go quiet), runs a sync — so it doesn't fire mid-copy. You choose how long to wait for things to settle: a debounce of 5, 10, or 30 seconds, or 1 minute, or a custom delay of 5–300 seconds. Next push sync shows the countdown. Ideal during an active show when files are being added continuously.

Version History

When enabled (Settings → Behaviour), ShowSync keeps previous copies of files on the Backup, so an overwrite never loses the older version.

Before each sync, ShowSync works out which files are about to be replaced and saves the existing Backup copy alongside the new one, with a timestamped name like report~sync-v~2026-06-16_14-30-05.pdf. The new version then takes the original's place, and the older copy stays in the same folder as a dated twin.

You choose how many versions to keep per file — 3, 5, 10, 15, or 20 (default 3). Once the limit is reached, ShowSync removes the oldest copies after each sync. There's no time limit — only the count matters.

What it covers

Version History applies to files that are changed or overwritten. Because ShowSync is additive — it never deletes files on the Backup to match the Main — files you delete on the Main are not removed or versioned on the Backup; they simply remain. This keeps your Backup safe: a deletion on the Main can never wipe files from the mirror.

Verifying a backup

To confirm the Backup matches, click Verify on the Main. While it runs you'll see Verifying… (checks every file) and a Cancel Verify button. It reports one of:

Fast vs Deep verify

You can choose how thorough Verify is, under Settings → Behaviour → Verify:

Verifying from the Backup

The Backup has its own Verify Backup button. It shows two lines:

• This Mac's copy: — a check of the data the Backup keeps: "Intact — all stored data re-checked, no corruption found", "Nothing stored to check yet" (normal with Save disk space on), or "Backup copy is damaged — re-sync recommended".
• Compared with the Main: — the Main's comparison of the source folder against the Backup, in the same words the Main uses. If the Main isn't connected it says "The Main isn't connected".

Fetch from Backup

Need a file back from the Backup during a show? Fetch brings the files you choose from the Backup to the Main — no role switch, no re-pairing.

1. On the Main, click Fetch (next to Sync Now and Verify). The Fetch from Backup screen lists the Backup's files.
2. Tick the files or folders you want — ticking a folder takes everything in it. Use Search files… to find something, and Refresh to list the Backup's files again.
3. Check Fetch to. Files go to a From Backup folder beside your source folder by default; click Choose… to pick another. It can never be inside the source folder, so fetched files are never synced back.
4. Click Fetch N files. Progress shows as it runs, and Cancel Fetch stops it. When it's done: ✓ Fetched N files · size.

Delete from Backup

Delete from Backup removes files from the Backup Mac — an old show, a wrong upload — without walking over to it. A sync never deletes anything; this is the only way files are removed from the Backup, and only the files you choose.

1. On the Main, click the trash icon at the bottom of the popover. The Delete from Backup screen says "Deletes on the Backup only. Nothing on this Mac is touched."
2. Tick the files or folders to remove (Search files… and Refresh work as in Fetch), then click Delete N files….
3. Confirm "Delete N files (size) from [Backup]?" by typing DELETE — "Type DELETE to remove these items from the Backup. This can't be undone." — and clicking Delete.
4. The result reads ✓ Deleted N files · size from the Backup.

History

Click the clock icon at the bottom of the popover to open History. It starts empty — "No sync history yet".

Each row on the Main shows the time (and the date if it wasn't today), a tag — Manual, Auto or Push — then N files · X sent, how long it took, and via ‹adapter›. The file count is the files that actually had data sent, not the folder total. The icon shows the outcome:

The Backup has its own History, tagged Receive, Delete and Fetch — for example "Received N files · size from [Main]", "N files deleted by [Main]", "N files fetched by [Main]". A sync that brought nothing new adds no row there.

Reading the status

The menu-bar icon is an up arrow in a circle on the Main and a down arrow on the Backup. Its colour tells you the state at a glance:

Green, orange and red stay until you open the popover; then the icon goes back to plain. ShowSync doesn't send macOS notifications — the icon and the popover are where status shows.

In the popover

The Main's header reads Ready (green when it's ready to sync, grey while setup is incomplete), Checking for changes…, Syncing, Synced, Failed or Cancelled — or, when something's wrong, Not connected, Backup app not running, Selected network not found or Not discoverable. The Backup's header reads Ready, Receiving, Not discoverable or Main not connected. If Sync Now can't run, the reason appears under the buttons (see Troubleshooting).

Connection Info

Both popovers have a Connection Info fold-out — click it to open or close it; ShowSync remembers which you chose.

On the Main

• Backup Network Discovery — the Backup's name (Automatic discovery).
• Backup IP — marked (auto) when it was found automatically.
• Connection status — Connected, Not Connected or Checking…, or Backup app not running / Selected network not found.
• Source Folder — marked Missing if it can't be found.
• Backup Folder — with its free space, or (drive unavailable) / Backup not reachable.
• This Mac's IP — with the adapter in use.
• Main version and Backup version — with · Match or · Different.

On the Backup

• Network Discovery and This Mac's IP.
• A Main block — the paired Main's name, whether it's connected, and Last seen with the time.
• Main version and Backup version, as on the Main.

Trial & license

The full Main (sending) capability is unlocked by a 14-day free trial or a purchased license. Open Settings → License.

Starting a free trial

Click Start free trial to begin a 14-day trial on this Mac, or paste a key you've been given into Enter license key and click Activate. After activating, you'll see "Activated — relaunch to enable Main mode." — quit and reopen ShowSync to switch into Main.

What the status line means

Two machines per license

One license activates ShowSync on up to two Macs. If you try to activate a third, you'll see "Already active on the maximum 2 Macs."

Backup-only mode

When a Mac has no active trial or license, ShowSync runs in Backup-only mode: it can still receive files (so a free machine is always useful as a Backup), but the Main sending features are hidden. You'll see the note "Backup-only — activate a license to enable Main mode."

Start a trial or activate a license, relaunch, and the full Main capability returns. Your saved role and settings are never lost while in Backup-only mode.

Settings reference

Settings are opened from the gear icon in the popover. The Main has six groups; the Backup has five.

On the Main

On the Backup

Reset to Defaults (with a confirmation) erases settings, the pairing and sync history and returns ShowSync to its first-launch state. It does not delete your synced files, and it can't be used while a sync is running.

Speed Tests

On the Main, Settings → Speed Tests has two quick checks to run before a show — run them when nothing else is running.

Adapter Speed — Test Speed

Click Test Speed. It "Measures the selected adapter to the Backup over the real backup path — plug in an adapter and compare before a show." The result reads like 300 MB/s · ≈34 sec for 10 GB · via Thunderbolt Bridge. It stays on screen until you test again or pick a different adapter. If the link is very slow you'll see "Link too slow — under 5 MB/s".

Disk Speed — Test Disks

Click Test Disks. It "Measures the Backup's drive and this Mac's source drive with the cache bypassed." You'll see Testing the Backup's disk… then Testing this Mac's disk…, and a result for each. With a Test Speed result on screen it names the weakest link: "Slowest part: … A sync cannot go faster than this." Without one it says "Run Test Speed too to see the slowest part."

Staying awake

While a sync, Fetch, Verify or Delete from Backup runs on the Main — and while the Backup is receiving — ShowSync stops the Mac from going to sleep on its own, so a long transfer isn't cut off by idle sleep. It lets go as soon as the transfer ends. There's no setting and nothing on screen.

Updates

Under Settings → About, click Check for Updates. ShowSync checks for a newer version and reports one of:

ShowSync doesn't check or install updates on its own — this button is how you check, and Download opens the download link in your browser. Update both Macs so they run the same version.

Network & security

For best performance and security, run ShowSync on a dedicated, hardwired network. All transfers between the two Macs are encrypted with TLS 1.3, and a transfer only ever goes to the Mac you paired with. Trust is key-based, with a human-confirmed pairing step — no passwords are stored.

ShowSync uses ShowNetwork, Remember Live's interface-binding technology, to keep show traffic on the network interface you choose — so your sync stays on your dedicated show network. Pick the interface under Settings → Connection → Network Interface (see Choosing the network).

ShowSync pairs one Main with one Backup, Mac to Mac, on your local network. There's no cloud service in between.

Troubleshooting

The Backup doesn't appear when pairing

Confirm both Macs are on the same network, ShowSync is running on both, and both use the same Network Interface. Check that Local Network access is allowed for ShowSync on both Macs — the Main may say "Still looking — if nothing appears, allow Local Network access for ShowSync in Privacy & Security." If it still doesn't show, pair by hand with Set Up Manually (see Pairing the two Macs).

"macOS may be blocking local network access for ShowSync"

Click Open Privacy Settings and turn ShowSync on under Local Network. If it's already on, switch it off and on again, then quit and reopen ShowSync. During manual setup on the Backup the same advice appears as "Couldn't Reach the Main".

"Backup not reachable on selected network"

The Backup can't be reached on the chosen network interface. Check cabling/Wi-Fi, and confirm the Network Interface in Settings → Connection matches the network the Backup is on.

"Selected network not found"

The adapter you picked isn't connected. Reconnect it (plug the cable back in), or switch Network Interface to Automatic.

"Backup app not running"

The Main can't see ShowSync on the Backup Mac. Open ShowSync on the Backup and check it's in the Backup role.

Sync won't start

ShowSync tells you why inline — common reasons: "Choose a source folder," "No Backup selected," "No Backup user set," (Automatic discovery only) "Connection not yet set up," or "Backup not reachable on selected network." Resolve the stated item and try again.

A sync was refused for space

The message says how much space the sync needs and how much to free on the Backup. The Backup also shows "Not enough space on the backup drive. Free up space to resume backups." when it's below its Minimum Free Space. Free up space on the Backup's drive, then sync again.

"Show folder too big for one sync"

The source folder has more in it than one sync can carry. Move recordings that are already on the Backup out of the source folder (they stay on the Backup), then sync again. If the message says the Backup's version is the limit, update ShowSync on the Backup.

"Sync interrupted — files may be incomplete"

The connection dropped and the automatic retries couldn't finish the sync (see Retry & resume). Check the connection and click Sync Now — it picks up where it left off.

The first Fetch after an update fails

Press Fetch again — it normally works the second time. If it keeps failing, switch ShowSync's Local Network access off and on in Privacy & Security on the Backup Mac, then quit and reopen ShowSync.

"Already active on the maximum 2 Macs"

Your license already covers two machines. To move it to a different Mac, deactivate it on one of the current machines first, or contact Remember Live.

"This Mac has already used its free trial."

Each Mac gets one free trial. Enter a license key to keep using Main mode.

"That key is for another Remember Live app."

The key belongs to a different Remember Live product. Check you're entering your ShowSync key.

"Couldn't reach the licensing server"

Activation needs internet once. Connect to the internet to activate or start a trial; afterwards ShowSync works offline.

"This Folder Can't Receive Files Over the Network"

You chose a destination macOS protects (Documents, Desktop, or Downloads). Pick a folder inside your home directory (such as the default ~/Sync) or on an external drive instead — external drives need one extra macOS setting, and ShowSync shows you how when you select one.

The Main Mac only shows Backup features

It's in Backup-only mode — start a trial or activate a license in Settings → License, then relaunch.