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Yuexian Tech
Free Online Tools
FREE Yuexian Tech Free Image Tools
Crop and flatten documents, adjust all four corners
Crop regular images or correct the perspective of a photographed ID or document locally.
Drop images here
or click to select multiple images
JPG · PNG · WebP · GIF · BMP supportedCUT
Local processingCrop Images
Drag the four corners to choose the exact area, or drag inside the frame to move it.
Choose or drop one image
JPG, PNG, WebP, GIF, and BMP are supported. Your image is not uploaded.
Four-corner crop
Crop regular images by dragging any corner or moving the frame.
Document flattening
Estimate four document corners, adjust them manually, and view a live flattened preview.
Local HD export
Perspective correction and JPG, PNG, or WebP export happen entirely in your browser.
Free image cropper and document straightener
Detect document corners, adjust them, and flatten perspective
Regular crop mode supports free, 1:1, 4:3, 3:4, and 16:9 crops. Document mode estimates the four corners of a photographed ID, licence, contract, or paper document. Drag each numbered handle onto the true edge and check the flattened preview before exporting JPG, transparent PNG, or WebP. Detection and correction happen locally.
Is my document uploaded?
No. Corner detection, cropping, perspective correction, and export happen locally in your browser.
What if automatic corner detection is inaccurate?
Drag the four numbered handles until the blue quadrilateral follows the real document edges.
When should I use document flattening?
Use it for angled photos of IDs, licences, contracts, or paper documents. Curved, reflective, or hidden edges may need more manual adjustment.
Yuexian Tech · Support
Product and development support by Yuexian Tech
Mini-program, app, and custom software development for Zhengzhou and remote clients in Beijing, Shanghai, Hangzhou, and beyond.
China Social Insurance Calculator
Estimate employee and employer social insurance plus housing fund contributions with editable city presets.
The published period and base range appear here
After employee contributions, before IIT: ¥0.00
Contribution breakdown
Updated from the current inputsContribution bases usually change annually, while some rates vary by employer industry or temporary policy. These editable presets do not replace an authority determination.
This estimate excludes individual income tax, special deductions, supplementary medical plans, and supplementary housing funds. Follow the employer declaration, payslip, and official local system.