- Open the file in the canvas. Bemiv cropper is local, isolated and never touches the server.
- Frame the export rectangle. For batch-style cropping at the same aspect across many files, talk to us about scripted access.
- Apply rotate or mirror first; all canvas transforms execute before the export step.
- Lock numerical width / height in the toolbar so the export matches the destination platform exactly.
- Press Crop Image. The result writes to your downloads folder with no server-side trace.
Technical handbook from the Bemiv team
The following sections extend the quick steps above with the engineering detail we would give to a colleague. Bemiv Bulk Converter is built around high-volume bulk image optimisation done deterministically; every recommendation below is written against real workloads, not generic marketing copy. If anything conflicts with your in-house policy, your policy wins — but if you are starting from scratch, this is the baseline we ship in production.
Client-side privacy model
The Bemiv cropper runs in your browser: the bitmap is decoded by the JavaScript runtime, manipulations happen in an HTML5 canvas, and the export writes a new Blob for download. Bytes are not transmitted to our conversion cluster during the crop operation itself. That makes the cropper suitable for pre-publication material you are not yet willing to push to a shared server, provided you trust the security posture of your local browser and extensions.
Aspect ratios and composition
When preparing assets for responsive layouts, decide whether you need one master crop or multiple art-directed crops. Browser srcset cannot invent a new composition; it only rescales. If marketing requires a tall vertical crop for Stories and a wide crop for the web hero, produce two crops deliberately rather than expecting CSS to solve it. The cropper’s numeric width/height fields help you lock an exact output size after the interactive frame is chosen.
Colour and exporting
Most browsers decode incoming photos to sRGB for canvas operations unless explicitly colour-managed. Extremely wide-gamut assets may therefore appear subtly different than in a fully colour-managed desktop editor. For final colour-critical editorial, verify on a calibrated display. Export formats: PNG preserves alpha; JPEG does not; WebP can preserve alpha if chosen as the export format in your browser pipeline (the Bemiv crop UI offers PNG/JPEG/WebP as appropriate).
Downstream conversion
Many teams crop here and convert to JPG or WebP through the Bemiv converter in a second step. That two-step flow mirrors professional tooling (select pixels, then encode). Keep lossy steps minimal: one crop, one lossy encode is better than crop, save JPG, re-upload elsewhere, save JPG again.
Accessibility and input devices
Touch dragging is supported for mobile framing. Keyboard precision may be lower; for sub-pixel alignment, prefer desktop. If you need repeatable crops across hundreds of files, consider scripting with a desktop batch tool; this interface optimises for human framing decisions on individual photos.