Image Compression
Adjust JPG / WebP quality to reduce website and sharing image sizes.
WUCJ Tools Series
Compress, convert, crop and batch-process images in one place.
Process JPG, PNG and WebP images directly in your browser. Most features do not require uploading private photos and work on mobile and desktop.
✓ Local-first
✓ Batch Processing
✓ Mobile Friendly
🔒 Local-first
Keep your images on your device whenever possible
Compression, conversion, resizing and rotation run in the browser. Unless a future feature explicitly requires cloud processing, WUCJ Image Tools does not intentionally upload your images.
Ad Space
Banner ad space available after AdSense approval
IMAGE WORKSPACE
Image Workspace
Add one or more images, apply common format, quality, size and rotation settings, then download individually or in batches.
Image List
No images added yet
🖼️
Add Images First
Drag in multiple photos, then compress them in batches, convert to WebP or download a ZIP.
JPG / PNG / WebP Converter
Quickly convert between common image formats for websites, social media and documents.
Resize
Set width and height with optional aspect-ratio preservation.
Image Crop
Crop precisely using X, Y, width and height for fixed-size requirements.
Rotate & Flip
Rotate left/right or flip horizontally/vertically, and combine with other processing.
Images to PDF
Convert multiple images into a PDF, one centered and scaled image per page.
Compress to Target KB
Set a target file size; JPG / WebP will automatically try to reach the requested range.
Social / ID Photo Sizes
Quickly apply Instagram, Stories, Facebook, YouTube and common ID-photo presets.
Text Watermark
Customize watermark text, position and opacity for websites, work images and shared graphics.
Batch ZIP Download
Download processed images as one ZIP instead of saving each file separately.
Local-first
Processing runs in the browser, reducing the need for private photos to leave your device.
Frequently Asked Questions
Image Tools FAQ
Common questions about mobile image processing, conversion, compression, privacy and downloads.
Does WUCJ Image Tools upload my photos to a server?
Core image processing runs locally in your browser. Original images do not need to be uploaded to WUCJ Image Tools servers, although the website, analytics and advertising services may still use the network.
Can I select photos directly from my phone gallery?
Yes. Modern Android and iPhone browsers can select photos directly from your gallery for compression, conversion, resizing, visual crop, rotation, watermarking and download.
What is the difference between JPG, PNG and WebP?
JPG is suitable for photos and smaller files; PNG works well for transparency, icons and lossless graphics; WebP is often ideal for websites because it balances quality and file size.
Can I compress photos below 300KB or 500KB?
Yes. Choose JPG or WebP, enter a target size in KB, and the tool will try to adjust quality automatically. For very large images, reducing pixel dimensions first usually works better.
Why doesn't target-KB compression always work for PNG?
PNG compression works differently from JPG and WebP, so browsers cannot control file size with a simple quality percentage. For significant reduction, convert to WebP or JPG.
How do I use visual crop on mobile?
After adding an image, choose Visual Crop on its card, then drag over the preview with touch or mouse. Choose free ratio, 1:1, 4:5, 16:9 or 9:16 and apply the crop.
What are the sizes for Instagram square, portrait and Stories?
Presets include 1080×1080 square, 1080×1350 portrait and 1080×1920 Stories / Reels, available from Quick Sizes.
Does converting to WebP reduce image quality?
Lossy compression may slightly change quality depending on the setting. For typical web images, start around 75%–85% and compare file size and visual quality.
Are EXIF and GPS metadata preserved after conversion?
Canvas re-export creates a new file and generally removes original EXIF, GPS and similar photo metadata. For highly sensitive use, verify the downloaded file with a dedicated metadata tool.
Why do Image-to-PDF or ZIP features need internet access the first time?
ZIP and PDF features currently load JSZip and jsPDF from a CDN, so the libraries require internet access on first load. Image content is still processed in your browser.
Can I process many images at once?
Yes. Add multiple images, apply common format and quality settings, process them together and download a ZIP. Large batches or very high-resolution images may be limited by mobile memory.
Is it normal for a processed image to become larger?
Yes. Converting JPG to PNG, increasing pixel dimensions or using very high JPG / WebP quality can increase file size. The list shows original and processed sizes for comparison.
Where are downloaded images saved?
On phones, downloads usually appear in the browser's downloads list or Downloads folder. On iPhone, check Safari's download button or the Files app.
Is WUCJ Image Tools free?
It is currently free to use. Advertising may support site operations, and features or service terms may change over time.
PRIVACY FIRST
Image processing stays in your browser whenever possible
WUCJ Image Tools uses a local-first front-end architecture. Image reading, Canvas editing, format export, ZIP packaging and PDF creation run in your browser.
Note: this is an online website, so page assets, analytics and advertising services may connect to external networks; image tool features do not require sending original images to WUCJ Image Tools servers.
Free online image tools for everyday, work and web use
Use WUCJ Image Tools for JPG-to-PNG, PNG-to-JPG, WebP conversion or batch compression. It works on mobile and desktop and compares original versus processed file sizes.
For website images, WebP is often a good choice. Use PNG when you need transparency, or JPG with adjusted quality for general photos and smaller files.