How big a file can it check?

The free file tools on this site work on your own device, so the file never travels anywhere. That also means the limit is not set by UtilForge: it is the memory of your phone or computer. Here is what we tested, and what to do if a big file will not open.

The short answer. We did not set a size limit in the file tools. In our test, Release Check read a 250 megabyte PDF (Portable Document Format) file in under five seconds on a computer. Phones have less memory, so very large files may fail there.

Last tested 15 October 2026, in a desktop Chromium browser on a computer, with test files we made ourselves. We have not tested every tool on every phone, and a real document with hundreds of pages or large pictures takes longer than our one-page test files.

What we tested

We made four PDF files of 5, 25, 100 and 250 megabytes, each with one page and the rest filled with data, and opened each in Release Check. Every one was read and checked with the result “no problems found by these checks”, in 0.3, 0.6, 2.0 and 4.8 seconds. These times are for the simplest possible file. Treat them as proof that the tool does not refuse large files, not as a promise about how long yours will take.

Why a limit exists at all

A tool that does not upload your file has to hold the whole file in your device’s memory to read it. A phone with many apps open has less spare memory than a computer, so it runs out sooner. When that happens, a tool may show a message such as “Could not read the file into memory. It may be too large for this browser tab.”

If a large file will not open

1. Close other tabs and apps, then try again.
2. Try a computer instead of a phone, or a newer browser.
3. Make the file smaller first. Compress PDF shrinks a PDF on your own device.
4. Split the file into parts and check each part. The full version of Release Check checks whole folders at once.
5. Check one important page at a time. A page with a mistake on it is the one that matters.

Which tools read files

Release Check, Redaction Studio, Is It Really Blacked Out, Compress PDF and the iPhone photo converter all open your file on your own device. See how to tell whether a tool uploads your file.

Related guides

• Does this tool upload your file? How to tell before you use it
• What each redaction check looks for
• Test a redacted PDF file yourself
• All guides