What you see
On an image or PDF tool, a message such as “That file is 38.2 MB. The limit is 25.0 MB so your browser does not run out of memory.”
The limit for the image and PDF tools on this site is 25 MB. Each of those tools says so at the top of its page: “Files up to 25 MB“.
Why there is a limit
Your file is never uploaded: it is read whole into your browser’s memory and processed there. That memory is limited — on a phone, sharply — and the file usually takes far more of it than its size on disk. A photo is stored compressed, but to edit it the browser has to unpack every pixel: a 24-megapixel photo becomes about 96 MB of pixels whatever its file size, and an edit often needs two or three copies at once.
Past a point the browser does not slow down, it closes the tab, and the work is lost without a message. The limit stops a file before that happens.
Which tools have it
Most image tools, most PDF tools and the Multi Hash Generator.
The video tools have no size limit, because for a video the length matters far more than the file size. They work through a video piece by piece and warn you when one looks too heavy for your device.
Video to MP3 Converter and Detach Audio & Video take MP4 and MOV files of any size: they copy the picture without decoding it and hold only the sound in memory, and they warn you when a video is too long for your device. A WebM — or any other file that is not MP4 or MOV — works up to 500 MB, because its sound can only be read by loading the whole file. Above that they say “This file is too large to open here”.
What to do
- A large photo: make it smaller first with the Image Resizer or the Image Compressor, then use the tool you wanted. Most photos are far larger than anything they are shown at.
- A large PDF: save a smaller copy from the program that made it — most have a “reduced size” or “smallest file size” option when saving or exporting as PDF — or split it there into parts.
- A WebM over 500 MB, for the audio tools: convert it to MP4 with a desktop app such as HandBrake. An MP4 of any size works.
- A very long video, for the audio tools: cut out the part you need with the Video Trimmer, or split the video with the Video Splitter, then extract the sound from the parts.