Image Optimizer
Batch process your assets with lossless precision.
Drop images or folder here
JPG · PNG · WebP · HEIC · BMP · TIFF · GIF
Pick a preset, or set the controls below yourself.
OptiPress
About & Documentation
OptiPress v1.1.0 PRO
STABLE RELEASEOptiPress is a native desktop application purpose-built for professionals who need to compress images at scale — without sacrificing quality or workflow speed. Batch compress hundreds of images in seconds with fine-grained control over output format, dimensions, and file size.
Batch Processing
Compress entire folders in one click. Multi-threaded engine processes files in parallel for maximum speed.
Precision Control
Fine-tune quality, max file size, and output dimensions independently per batch run.
WebP Auto-Convert
Automatically convert any source format to WebP — the modern standard for web images.
Non-Destructive
Originals are never touched. All output goes to a separate directory you control.
perm_media Supported Formats
history Release History
HEIC/HEIF support, parallel batches, dark mode, presets
2026 · Current
New interface, export formats, cancel, settings persistence
2026
Initial release — batch compression engine
2026
Coming Soon
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OptiPress is a product of Mackstroke Labs — building precision tools for digital professionals.
open_in_new labs.mackstroke.com© 2026 Mackstroke Labs. OptiPress is released under the MIT License.
OptiPress
Settings Dashboard
Account & Active Device
Sign in with Google or Email to unlock image compression.
Global Preferences
Default Output Directory
Where compressed images are saved when no output folder is set per-batch
Appearance
System follows your Windows light/dark setting
Output Filename
Use {name}
for the original name and
{ext}
for the extension. A suffix lets you save into the source folder safely.
photo.jpg → photo.jpg
Default Quality Level
85%Compression quality applied per batch. Higher = better image, larger file.
Export Format
Output file format applied to all exported images
Application
OptiPress
Product Updates
Product Updates
Stay up to date with the latest features, improvements, and bug fixes. We're constantly working to make your image optimization faster and more precise.
Faster, Darker, Safer
August 6, 2026- speed Batches now compress in parallel across your CPU cores — measured 9.5× faster on a 40-image run.
- palette Light and dark themes, with a System option that follows your Windows setting.
- auto_awesome Presets — Web, Email and Archive set every control in one click.
- file_copy Filename templates, which make saving into the source folder safe.
- bug_report The export format selector had stopped working — every batch fell back to the original format. Fixed.
- bug_report Max file size was silently ignored for PNG, BMP, TIFF and GIF. It now applies to every format.
- bug_report The Explorer right-click entry opened an empty window instead of loading what you selected.
- bug_report Files that grew when re-encoded are now kept as the original instead of reported as a saving.
- shield The app no longer contacts the internet at all — fonts and styles ship with it, so it looks right offline.
- settings Settings moved to your user profile, so they survive reinstalls and work under a shared install.
- rocket_launch Launch on startup now actually applies, and the non-functional GPU toggle was removed.
New Interface
June 2026- web Rebuilt interface, replacing the original widget-based window.
- tune Export format selector (Original, JPG, PNG, WebP) replacing the WebP-only toggle.
- cancel Cancel a running batch, drag and drop, and settings that persist between sessions.
- package_2 Windows installer with Start Menu shortcut and an optional Explorer right-click entry.
Initial Release
March 2026- flag First release. Batch compression for JPEG, PNG, WebP, BMP, TIFF and GIF.
- flag Quality slider, max file size, max dimensions, and a WebP conversion toggle.
- flag Non-destructive output — always writes to a separate directory.
OptiPress
Help Center
Help Center
Everything you need to get the most out of OptiPress — step-by-step guides, settings explained, keyboard shortcuts, and answers to common questions.
play_circle Quick Start Guide
Add your images
Click Select Images in the sidebar to pick individual files, or Select Folder to recursively scan an entire directory. You can also drag-and-drop files onto the drop zone — it opens the picker automatically. The source badge updates with the exact count detected.
Choose an output directory
Click Browse next to the Output Directory field and pick any folder. OptiPress never writes to your source location — it always outputs to a separate directory you control. To set a permanent default, go to Settings → Default Output Directory.
Adjust compression settings (optional — defaults work great)
Use the Quality slider (85% recommended), set a Max Size ceiling if needed, limit dimensions for web-optimised output, and pick an export format. WebP is on by default and gives 25–35% better compression than JPEG at the same visual quality.
Start batch processing
Click Start Batch Processing (or press Ctrl+Enter). The results table fills row by row showing each file's original size, compressed size, and % reduction. A progress bar and live counter run at the bottom. When done, click Open Folder to jump straight to your output files.
tune Settings Explained
keyboard Keyboard Shortcuts
All shortcuts are active any time an input field is not focused. Shortcuts that navigate automatically switch to the Home view before acting.
quiz Frequently Asked Questions
No — OptiPress is strictly non-destructive. It always writes to a separate output directory you choose. Your source files are never modified or deleted. The only overwrite risk is if you deliberately point the output folder at your source folder, which the app warns about before starting.
It's a hard ceiling on the output file size. After the initial save, if the file still exceeds the limit, OptiPress automatically re-saves it at progressively lower quality — dropping 5 points per attempt — until the file fits or quality reaches the minimum (10). Set Max Size to 0 to disable the constraint entirely.
WebP delivers 25–35% better compression than JPEG at the same visual quality. It also supports transparency (like PNG) and is supported in all modern apps and browsers. It's the best all-around format for web assets, social media, and storage. Use JPG only if a downstream tool explicitly requires it.
Yes. Click the Cancel button that appears during processing, or press Escape. The current image finishes saving cleanly, then the batch stops. The results table shows exactly how many files completed before cancellation.
No. Errors are per-image and non-fatal. If a file is corrupted, has an unsupported color space, or can't be opened, an error row appears in the results table and OptiPress moves straight on to the next file. A batch of 500 images won't stop because of one bad file.
Settings are saved per-user in your system configuration directory: %APPDATA%\OptiPress\settings.json on Windows (~/Library/Application Support/OptiPress on macOS, ~/.config/OptiPress on Linux). They survive app updates and reinstalls.
Go to Settings → Default Output Directory, click Browse, and pick your folder. Once saved, that folder is used automatically whenever you start a batch without specifying an output directory in the Home panel.
Max Width and Max Height set an upper bound — images smaller than those values are left at their original size. Images that exceed either limit are scaled down to fit within the bounding box while preserving the original aspect ratio. LANCZOS resampling is used for the highest-quality downscale. Set either value to 0 to skip that constraint.
lightbulb Tips & Best Practices
Converting to WebP before uploading to a website or CMS can cut page load times significantly with no visible quality loss.
Most social platforms downsample images anyway. Setting Max Width to 1920 px prevents uploading unnecessarily large originals.
Human vision can barely distinguish differences above 80%. Dropping from 100% to 80% typically halves file size with no perceptible quality loss.
OptiPress strictly prevents source file overwrite. When saving into the same folder, configure a filename template like {name}_compressed{ext}.