How our file tools work
A transparent explanation of browser processing, conversion engines, output quality and technical limits.
Image processing
Image tools use browser decoding and Canvas APIs for resize, crop, transparency, effects, compression and common format conversion. Re-encoding can remove metadata, but it cannot recover information already lost in a source image.
PDF structure versus PDF rendering
pdf-lib is used for structural jobs such as merging, reordering, watermarks and page sizing. PDF.js is loaded only when a page must be rendered to pixels, such as PDF-to-image or raster compression.
Target file size
Exact byte targets cannot always be reached. Target-size tools search quality settings and, when needed, dimensions or render scale, then report the actual generated size.
Video and audio conversion
Media conversion uses a locally hosted FFmpeg WebAssembly build. It can be computationally expensive and is deliberately loaded only on media-tool pages.
Structured data files
JSON, CSV and XML tools parse input locally. Conversions are intentionally conservative because not every nested structure maps perfectly between formats.