How to deploy a Flask app for free from a ZIP

What the Free plan includes.

Sitedropper Free is a $0 plan for a small real deployment workflow. The dashboard is the source of truth for the current ZIP limit shown beside Choose ZIP.

• Up to 3 projects
• 30 deployments per month
• Draft, Password protected, and Public sharing
• Sitedropper URL

Before you build.

Python server projects do not produce a browser build folder. The local check installs the exact requirements, compiles/imports the source, and starts the conventional Flask entry point.

• Flask declared in requirements.txt.
• A conventional app.py with an importable Flask application.
• Templates and static folders stored with the source.
• A stateless app that does not depend on local SQLite or uploaded files.

Build and check Flask locally.

Run these commands from the project root. Finish the local check before creating the archive so the deployment is not the first place a dependency, compile, or startup error appears.

The final server command stays running. Open the local URL in another terminal or browser, complete the checks, then stop it with Ctrl+C.

macOSWindowsLinux

macOS

Check Flask on macOS

Create a disposable virtual environment in Terminal, install the exact requirements, run the framework check, and start the same entry point you plan to upload.

Check Flask on macOSCopy Check Flask on macOS code

python3 -m venv .venv
. .venv/bin/activate
python -m pip install --upgrade pip
python -m pip install -r requirements.txt
python -m py_compile app.py
python -c "from app import app; print(app.name)"
python -m flask --app app run

Windows

Check Flask in PowerShell

Create a disposable virtual environment in PowerShell, install the exact requirements, run the framework check, and start the same entry point you plan to upload.

Check Flask in PowerShellCopy Check Flask in PowerShell code

py -m venv .venv
.\.venv\Scripts\Activate.ps1
python -m pip install --upgrade pip
python -m pip install -r requirements.txt
python -m py_compile app.py
python -c "from app import app; print(app.name)"
python -m flask --app app run

Linux

Check Flask on Linux

Create a disposable virtual environment in a terminal, install the exact requirements, run the framework check, and start the same entry point you plan to upload.

Check Flask on LinuxCopy Check Flask on Linux code

python3 -m venv .venv
. .venv/bin/activate
python -m pip install --upgrade pip
python -m pip install -r requirements.txt
python -m py_compile app.py
python -c "from app import app; print(app.name)"
python -m flask --app app run

Use one dependency workflow: keep the lockfile that matches the selected package manager and do not mix install commands.

Create the ZIP on your operating system.

Package reviewed source and build metadata; use the exclusions to keep local-only files out. The Windows and macOS recipes include graphical menu guidance, while the commands remain the precise archive contract.

No command line required

Directly create the ZIP in your file system.

First create and inspect a clean staging folder containing only the required source, manifest, configuration, and entry-point files. In Windows File Explorer, right-click the reviewed selection and choose Compress to → ZIP File. On macOS, Control-click the reviewed selection and choose Compress Items.

Open the resulting archive before upload. If an outer folder wraps the expected files, recreate the ZIP by selecting the folder’s contents instead.

Or create and inspect the ZIP from the command line.

macOSWindowsLinux

macOS

Compress the reviewed source in Terminal

The exclusions keep common dependencies, caches, local data, and secrets out. Finder users must first make and inspect an equivalent clean staging folder, then select its contents, Control-click, and choose Compress Items—not compress the raw project folder.

1. Run from the project root.
2. Inspect project-specific local files before upload.
3. Confirm the manifest, lockfile or requirements, source, and entry point are present.

Compress the reviewed source in TerminalCopy Compress the reviewed source in Terminal code

if [ -e site.zip ]; then echo "site.zip already exists. Move or rename it before continuing." >&2; exit 1; fi
zip -qr site.zip . -x ".venv/*" "venv/*" "node_modules/*" ".git/*" ".next/*" "dist/*" "build/*" ".cache/*" ".turbo/*" "__pycache__/*" "*/__pycache__/*" "*.py[cod]" ".pytest_cache/*" ".mypy_cache/*" ".env" ".env.*" "*/.env" "*/.env.*" ".npmrc" "*/.npmrc" "*.sqlite" "*.sqlite3" "db.sqlite3" "*.log" ".DS_Store" "*/.DS_Store" "site.zip" ".sitedropper-package/*"
unzip -l site.zip | head -60

Windows

Stage and compress the source in PowerShell

A clean staging folder prevents dependencies, caches, local databases, and secrets from entering the ZIP. For File Explorer, stop after robocopy, inspect the staging contents, select them, right-click, and choose Compress to → ZIP File; never compress the unreviewed project folder.

1. Run from the folder containing the manifest or requirements.txt.
2. Review the staging folder created beside the project before upload.
3. The command intentionally leaves the staging folder in place and never deletes it automatically.

Stage and compress the source in PowerShellCopy Stage and compress the source in PowerShell code

$ProjectRoot = (Resolve-Path .).Path
$ProjectName = Split-Path $ProjectRoot -Leaf
$Stage = Join-Path (Split-Path $ProjectRoot -Parent) "$ProjectName-sitedropper-package"
if (Test-Path $Stage) { throw "$Stage already exists. Move or rename it before continuing." }
if (Test-Path .\site.zip) { throw "site.zip already exists. Move or rename it before continuing." }
robocopy $ProjectRoot $Stage /E /XD .venv venv node_modules .git .next dist build .cache .turbo __pycache__ .pytest_cache .mypy_cache .sitedropper-package /XF .env .env.* .npmrc site.zip *.pyc *.pyo *.sqlite *.sqlite3 db.sqlite3 *.log
if ($LASTEXITCODE -ge 8) { throw "robocopy failed with exit code $LASTEXITCODE" }
Add-Type -AssemblyName System.IO.Compression.FileSystem
$Archive = Join-Path $ProjectRoot "site.zip"
[System.IO.Compression.ZipFile]::CreateFromDirectory($Stage, $Archive)
tar.exe -tf .\site.zip

Linux

Compress the reviewed source in a Linux terminal

The exclusions keep common dependencies, caches, local data, and secrets out. Install your distribution’s zip package first if needed.

1. Run from the project root.
2. Inspect project-specific local files before upload.
3. Confirm the manifest, lockfile or requirements, source, and entry point are present.

Compress the reviewed source in a Linux terminalCopy Compress the reviewed source in a Linux terminal code

if [ -e site.zip ]; then echo "site.zip already exists. Move or rename it before continuing." >&2; exit 1; fi
zip -qr site.zip . -x ".venv/*" "venv/*" "node_modules/*" ".git/*" ".next/*" "dist/*" "build/*" ".cache/*" ".turbo/*" "__pycache__/*" "*/__pycache__/*" "*.py[cod]" ".pytest_cache/*" ".mypy_cache/*" ".env" ".env.*" "*/.env" "*/.env.*" ".npmrc" "*/.npmrc" "*.sqlite" "*.sqlite3" "db.sqlite3" "*.log" ".DS_Store" "*/.DS_Store" "site.zip" ".sitedropper-package/*"
unzip -l site.zip | head -60

Inspect before upload: compare the ZIP listing with the archive tree below and remove dependencies, caches, local data, and secrets.

Check the archive root.

Do not include .venv, __pycache__, .env files, SQLite files, logs, or local uploads. Flask and its production dependencies must be pinned in requirements.txt.

site.zip
├── requirements.txt
├── app.py
├── templates/ (when used)
├── static/ (when used)
└── application modules

Upload the Flask ZIP to Sitedropper.

Create a Draft project, upload site.zip, follow the deployment, and open the generated URL only after the progress reaches Ready.

The dashboard screenshots use fictional project and account data. Yellow outlines identify the documented controls.

1. 01

   Create a project

   Open Projects, choose New project, enter a name, and select the highlighted Create project action. New projects begin as Draft.

   

2. 02

   Upload the ZIP

   Open the project’s Upload and deploy card, then select the highlighted Choose ZIP control or drop the archive into the same area.

   

3. 03

   Open the deployed site

   Wait for Analyze, Build, and Deploy to finish. Then use the highlighted Open Sitedropper site action to review the generated URL.

   

Dashboard screenshot

Dashboard action

Close ×

Check the Flask result.

Use the deployed URL like a visitor rather than relying only on the successful status.

• Open / or the app’s documented health route.
• Render one template and load one static asset when used.
• Exercise a route that does not depend on a missing local database.
• Confirm imports work from the archive root and do not rely on your IDE path.

Update Sitedropper Project settings.

Project settings are separate from framework configuration. Update the project name or description, keep Draft while reviewing, then choose Password protected or Public only when that matches the intended audience. Free does not include Private sharing by email, URL customization, or custom domains.

The dashboard screenshots use fictional project and account data. In the first settings image, the existing yellow outline marks Open site; the Project settings card is visible below and is identified by the instructions.

1. 01

   Review Project settings

   The Project settings card is below the project header. Update the name or description, review the generated URL, and keep the first deployment Draft while you test it.

   

2. 02

   Choose who can open the site

   Open Visibility. Free includes Draft, Password protected, and Public. Select Public only when anonymous access is intentional, then close the menu and choose Save changes.

   

Dashboard screenshot

Dashboard action

Close ×

Finish the change: close the visibility menu, select Save changes, and wait for the “Changes saved” confirmation before leaving the page.

Troubleshoot this Flask deployment.

Flask cannot find the application

Use the supported app.py convention with an app object, or use an existing Dockerfile for a different entry convention.

A module is missing

Add the package to requirements.txt and reinstall locally in a clean virtual environment.

Templates or static assets are missing

Keep their folders at the paths app.py expects and confirm they appear in the ZIP.

The app uses SQLite

SQLite/local databases are not supported by this stateless ZIP workflow. Remove the dependency or use a compatible external service.

Know the Free-plan boundaries.

• The application must be stateless on its local filesystem.
• Sitedropper does not provide an application database, cron process, or background worker in this ZIP workflow.
• Keep credentials and local environment files out of the archive.

The generated Sitedropper URL remains available on Free. Check the dashboard for current usage and upload limits before starting another deployment.

Flask deployment FAQ.