SIC! — Simple Image Converter

Overview

SIC! is a simple and accessible image format converter. It lets you convert images between popular formats, optionally resize them, and process multiple images at once.

Main window

The main window consists of the following areas:

Menu bar

Four menus at the top of the window:

• File — add images (from files, folders, or links), open Settings, or exit the application.
• Edit — remove selected or all images from the queue. This menu is disabled when the queue is empty.
• Convert — run conversion, create a multi-size ICO, or fit an image to a file size. This menu is disabled when the queue is empty.
• Help — open this manual, check for software updates, donate, or view the About dialog.

Image list

The left half of the window shows the batch queue as a table with columns: File Name, Format, Dimensions, Size, and Status.

Preview panel

The right half of the window displays a preview of the currently selected image.

Controls area

Below the image list and preview:

• Target Format dropdown — choose the output format.
• Resize checkbox — when checked, reveals the resize mode (Keep proportions or Crop) and Width/Height fields.

Conversion buttons

Convert Selected converts only the highlighted image; Convert All processes every image in the queue.

Status bar

At the bottom of the window, shows status messages such as conversion progress and results.

Installation modes

SIC! is available as an installer and as a portable ZIP archive. Both can be downloaded from GitHub Releases or the SIC! website.

SIC! can run in two modes:

Installer (default)

When installed normally, SIC! stores its configuration, converted files, and logs in %APPDATA%\Oire\Sic\. The default output folder is %APPDATA%\Oire\Sic\Converted\.

Portable

If a userdata folder exists next to the executable, SIC! runs in portable mode. All data (configuration, converted files, logs) is stored in that userdata folder instead of %APPDATA%. This lets you run SIC! from a USB drive or any folder without leaving traces on the system.

Adding images

There are several ways to add images to the queue:

Open files

Use File > Add Image (Ctrl+N) to open a file picker. You can select multiple files at once.

Add a folder

Use File > Add Folder (Ctrl+Shift+N) to add all images from a folder. You can choose which file types to include and whether to scan subfolders.

Add by link

Use File > Add Image by Link (Ctrl+L) to download an image from a URL and add it to the queue.

Drag and drop

Drag image files from File Explorer and drop them onto the image list.

Paste from clipboard

Press Ctrl+V to paste. SIC! supports pasting files (e.g., copied from File Explorer or Outlook), raw bitmap data (e.g., from Print Screen), and image links from the clipboard. If the clipboard holds text that isn't a valid link, SIC! tells you so instead of doing nothing.

Automatic clipboard detection

SIC! can watch the clipboard and offer to add an image, image files, or an image link automatically whenever its window opens or regains focus. This is off by default; turn on Detect images in clipboard in Settings. A Yes/No prompt always asks before anything is added, and the same clipboard content is offered only once, so it never nags you.

Converting images

1. Add one or more images to the queue.
2. Select the desired target format from the Target Format dropdown.
3. Click Convert All (Ctrl+Shift+F5) to convert every image in the queue, or select specific images and click Convert Selected (F5).

By default, converted files are saved to a Converted folder inside the application data directory. You can change this in Settings.

If a file with the same name already exists, SIC! will ask you whether to overwrite, rename (by adding a _1 suffix), or skip that file.

Converting an image to the format it is already in is skipped rather than performed: re-encoding it would only lose quality for no gain, so the queue simply reports Skipped (same format). If a resize is requested at the same time, the conversion does go ahead, and SIC! reapplies the original encoding quality so the image is not compressed harder than it already was.

Resizing

Check the Resize checkbox to enable resizing during conversion. Two modes are available:

Keep proportions (default)

Enter a width, a height, or both. The image will be scaled to fit within the given dimensions while preserving its aspect ratio. If you enter only one dimension, the other is calculated automatically.

Crop

Both width and height are required. The image is resized to cover the target dimensions, then cropped to the exact size.

When you select an image in the list with resize enabled, the width and height fields are pre-filled with the image's current dimensions.

Creating multi-size ICO files

To create an ICO file that contains multiple sizes (useful for application icons):

1. Select an image in the list.
2. Choose Convert > Create Multi-size ICO (Ctrl+Alt+F5).
3. Pick a preset or configure custom sizes in the dialog that appears.

The following presets are available:

Favicon

Generates sizes 16, 32, 48, and 64 pixels. A favicon is the small icon displayed in browser tabs, bookmarks, and address bars. This preset covers all the sizes commonly expected by web browsers.

Application icon

Generates sizes 16, 20, 24, 32, 40, 48, 64, and 256 pixels. This covers the full range of sizes Windows uses for application icons — from small taskbar icons to the large tiles shown in Explorer.

Custom

Lets you build your own list of sizes. Starts with the previously selected preset as a base, then you can add or remove individual sizes.

Fitting an image to a file size

Sites and forms often refuse an image above a certain size — "your avatar must be under 200 KB". Rather than guessing at formats and quality settings yourself, let SIC! search for a combination that fits:

1. Select an image in the list.
2. Choose Convert > Fit to File Size (Ctrl+Alt+Shift+F5).
3. Enter the Maximum file size in kilobytes. Optionally tick Limit width and enter a maximum width in pixels, for cases where the dimensions are capped too. Proportions are always kept.
4. Press OK. SIC! tries each enabled target format in turn and reports its progress, for example Checking AVIF (6/6).... You can cancel at any point.
5. Choose one of the results and press Convert.

Each result spells out exactly what you would get, for example WEBP — 1280x853, quality 82% — 195.4 KB (recommended) or PNG — 800x533, full quality — 187.2 KB.

Results are ranked so that the best one comes first and is marked (recommended): more pixels wins first, then higher quality, then the smaller file. That is usually what you want when facing an upload limit — a full-size image at slightly reduced quality beats a shrunken one at maximum quality.

A few things worth knowing:

• Every size listed is a real measurement, not an estimate. Nothing is written to disk during the search, and the file SIC! finally writes is byte-for-byte the one it measured.
• Only the formats ticked under Target formats to show in the list in Settings are tried.
• ICO and GIF are never used here. ICO cannot hold large images, and GIF is limited to 256 colors and ignores quality settings, so neither can honestly meet an arbitrary size budget. Both remain available as ordinary conversion targets. If they are the only formats you have enabled, SIC! tells you so instead of searching.
• For lossy formats (JPG, WebP, AVIF), SIC! also tries keeping every pixel and lowering quality instead of shrinking the image. Quality is never taken below 45%, and no image is shrunk below 16 pixels on its shorter side.
• The search performs many trial encodes and can take tens of seconds on a large photo; AVIF is by far the slowest format.
• If no format can meet the budget — say 5 KB for a 24-megapixel photo — SIC! reports that no fit was found instead of offering an unusable thumbnail.

The chosen result is saved using the usual output folder and filename-conflict rules, exactly like a normal conversion.

Settings

Open File > Settings (Ctrl+,) to configure SIC!. The dialog is organized into two tabs, General and Images. Press Ctrl+Tab to move between tabs.

General tab

Language

Choose the interface language. Select System to follow your Windows language setting.

Confirm on exit with non-empty queue

When enabled (the default), SIC! asks for confirmation before closing if there are images remaining in the queue. Uncheck this option to exit without a prompt.

Check for updates on startup

When enabled (the default), SIC! performs a single silent update check shortly after it starts. If the check cannot reach the network, it is ignored — it never interrupts startup or shows an error. Uncheck this option to skip the check at launch.

Check for updates in the background

Choose how often SIC! checks for updates while it is running: Once a day (the default), Every 3 days, Once a week, Once a month, or Never. Select Never to turn background checks off entirely. This setting is independent of the startup check — you can have either, both, or neither. A change takes effect immediately, without restarting the application.

Images tab

Output folder

Set a custom folder where all converted files will be saved. Click Reset to restore the default Converted folder inside the application data directory.

Save converted images in the same folder as the original

When enabled, each converted file is written next to its source file instead of into the output folder above. Images that have no source folder — clipboard captures and downloaded links — still go to the output folder. This option is off by default.

Detect images in clipboard

When enabled, SIC! offers to add usable clipboard content — an image, image files, or an image link — whenever its window opens or regains focus. A Yes/No prompt always asks before anything is added, and the same clipboard content is offered only once, so it never nags you. This option is off by default. See Adding images for details.

Target formats to show in the list

Tick the formats you want to see in the Target Format dropdown of the main window, and untick the ones you never convert to. At least one format must stay ticked. Leaving them all ticked also means that formats added in future versions of SIC! appear automatically.

Settings are stored in Sic.cfg inside the application data directory (see Installation modes for the exact location).

Software updates

SIC! can check for new versions automatically. By default an update check runs on startup and then once a day while the application is running, but both behaviors are configurable in Settings — you can turn the startup check off and choose the background frequency (or disable background checks entirely). You can always check manually via Help > Check for Updates.

When an update is available, SIC! shows a dialog with the new version number. You can choose to update, skip this version, or be reminded later. If you click Update, the new version is downloaded automatically. Once the download finishes, a confirmation dialog appears with Install and Cancel buttons. Clicking Install starts the installation.

Command-line usage

SIC! can also be used from the command line without opening the graphical interface. This is useful for scripting or batch processing.

sic -i input.png -o output.jpg
sic --input photo.bmp --output photo.webp
sic -i avatar.png -o avatar.ico --resize 128x128
sic -i photo.jpg -f png --resize 800x

--input, -i (required)

Path to the source image.

--output, -o

Path to the output file. The target format is inferred from the file extension.

--format, -f

Target format name (e.g., png, jpg). Use this instead of --output to auto-generate the output path.

--resize, -r

Resize the image. Format: WxH, Wx (width only), or xH (height only).

--crop, -c

Crop instead of scaling proportionally. Requires both width and height in --resize.

Either --output or --format must be provided (but not both).

Keyboard shortcuts

Supported formats

Troubleshooting

A cloud file cannot be loaded

Files stored in OneDrive or SharePoint that haven't been downloaded locally appear as cloud placeholders. SIC! will detect this and ask if you want to download them first.

Conversion fails for a specific file

Check that the file is a valid image and not corrupted. SIC! logs detailed errors to the logs folder inside the application data directory.

The output folder no longer exists

If the custom output folder has been deleted or moved, SIC! will warn you and fall back to the default Converted folder.