Every file you upload to a compression website makes the same journey: from your device, across the network, onto a server you know nothing about, and back. LetCompress removes the journey. Compression happens entirely inside your browser — the file never leaves your device, because there is no upload step to leave through.
How client-side compression works
Modern browsers ship with the building blocks of image and PDF processing: canvas APIs, encoders for WebP and other formats, and enough computing power to shrink a photo faster than it could be uploaded in the first place. LetCompress assembles those capabilities into a workflow — select files, adjust settings, watch sizes update, download results.
The practical consequences are immediate. There is no queue, because there is no shared server. There is no size quota, because the limit is your own device's memory. And the privacy posture is structural rather than promised: a tool with no upload pipeline cannot leak what it never receives.
Formats and what you can do with them
LetCompress handles PNG, JPG, WebP, and AVIF images, plus PDF documents. Output format is a first-class control: shrink a PNG for a web page, deliver a screenshot as WebP, or accept slightly lossy JPG encoding in exchange for a fraction of the original size. PDF compression trims document weight for email attachments and upload forms that still enforce limits from a decade ago.
Quality is an explicit control with a live size preview, and lossless options remain available for formats that support them. The tool never silently degrades a file — if you are trading quality for bytes, you decide exactly how much of each.
Batch workflows
Real compression jobs are rarely one file. A photo set from a weekend trip, a folder of screenshots destined for a bug report, a stack of scanned documents — these call for batch treatment. Select the files, set the quality once, and every file is processed with the same settings and downloaded together.
Because the work happens locally, a batch of large files is bounded by your hardware rather than by someone's per-upload limit or metered bandwidth. On a typical laptop connection, compressing locally is usually faster than uploading the originals would have been.
Privacy by architecture
Privacy policies are easier to write than to verify. "We delete your files after 24 hours" is a claim about behavior; client-side processing is a fact about design. For contracts, ID scans, medical records, children's photos, or anything else that should simply not travel, LetCompress offers the stronger guarantee: the file never left my computer.
The same logic applies offline. Once the page has loaded, the network can go away entirely — on a plane, in a basement, on conference Wi-Fi — and compression keeps working, because it never depended on the network in the first place.
When to reach for it
Keep it bookmarked for the recurring moments: an email attachment that exceeds the limit, a web form that rejects oversized uploads, a photo album that needs to fit in shared storage, a PDF that could be half its size with no visible difference. Free, no registration, and nothing to clean up afterwards — the quietest possible tool for one of computing's most repetitive chores.