PDF and image utilities that run entirely in the browser. No upload queue, no file-size ceiling, and nothing to delete from a server afterwards.
Most online PDF and image tools work by upload, process on a server, download. At that moment a copy of your file exists on someone else's machine, and when it gets deleted depends on that service's promise. For a contract, an ID document or a medical record, the structure itself is the problem.
The file tools here process inside the browser. WebAssembly together with the Canvas and File APIs do the same work on your machine, and nothing is sent over the network. The check is easy: disconnect from the internet and try again. Everything still works.
There are side benefits. With no upload-download round trip, large files finish faster, and there are no size caps or «three conversions a day» limits.
One word covers two operations: resizing (fewer pixels) and quality reduction (less information stored per pixel). When a photo is too heavy for the web, resizing usually comes first — going from 4000px to 1600px removes most of the weight on its own.
JPEG quality is not linear. Dropping from 100 to 90 nearly halves the file with almost no visible change; below about 70 you start seeing artefacts around edges. Somewhere around 80–85 is usually the right trade.
PNG behaves differently. It is lossless, which makes it inefficient for photographs and right for logos, screenshots and anything needing transparency. Saving a photograph as PNG typically produces a file several times larger than JPEG.
Merging is not concatenation — it rebuilds the page trees of several documents into one. That is why order can be chosen and why pages of different sizes survive intact.
Splitting is the reverse: pulling a page range out into a new document. Sending only the signature page of a contract, or lifting one chapter out of a hundred-page scan.
The two conversion directions are not symmetric. Images to PDF bundles pages without loss, but PDF to images rasterises vector content, so a resolution has to be chosen. Go high for print and low for screen.
HEIC, the default on recent iPhones, is considerably smaller than JPEG at equal quality. The problem is compatibility: older Windows installs, some web services and many official upload forms will not accept it.
The practical split is «keep HEIC, submit JPG». Converting costs a little quality, but not at a level that matters for a submitted photograph.
Capture metadata (EXIF) can survive the conversion. If a photo carries a location and you plan to publish it, check that first.
An ID photo is not just a millimetre size. Each country and purpose fixes the head-height proportion, the vertical eye position, the background colour and the margins, so cropping without the specification gets the application rejected. Pick a specification and the tool places the crop accordingly.
Making a GIF is the opposite kind of problem — a trade between size and smoothness. More frames look better and weigh more, and reducing to a 256-colour palette can turn gradients into visible bands. Short clips with strong contrast suit the format best.
Because everything runs locally, your device is the processing limit. Very large images and PDFs of several hundred pages consume a lot of memory, so an older machine or a phone may slow down or stall the tab. Split the work when that happens.
Optical character recognition on scanned pages, removing a password from an encrypted PDF, and verifying digital signatures are not provided.
Results are saved through the browser's normal download. The original is untouched, so verify the output before you clean up the source.