What the 35 MB limit covers
The limit is per PDF document as uploaded. A filing assembled from a main document and several attachments is measured piece by piece rather than as a single total.
Note that this is the federal district court, not the Los Angeles or Orange County Superior Courts. California's state courts run entirely separate electronic filing systems with their own figures, and the two are routinely confused because they cover overlapping geography.
Why a filing gets this large
Thirty-five megabytes is comfortable for text and tight for images. A brief exported directly from a word processor will not come close. A deposition exhibit scanned at 300 DPI in color will pass it inside about a hundred pages.
The single most effective change is usually resolution and color depth on the scan itself. A document scanned in color carries three bytes per pixel where greyscale carries one; for a page that is black text on white paper, most of that data records nothing but paper.
Compression after the fact does the same arithmetic in reverse. Resampling the embedded images from 600 DPI to 200 DPI removes roughly nine tenths of the pixels while leaving text on the page clearly readable at normal viewing size.
Checking the limit yourself
CM/ECF reports its own current ceiling. From the CM/ECF startup page, the Court Information link shows the Maximum PDF File Size the system will accept at that moment. That figure is authoritative for the system you are actually filing into, and it is worth a look whenever a filing is refused for size — districts raise these limits without much announcement, and a number you remember from last year may simply be out of date.
If the file is an exhibit
Lossy compression alters a file. Every byte of the output differs from the input, even where the page looks identical on screen, and that can matter if the document's authenticity is ever contested. ShrinkWrit shows the SHA-256 hash of the file you started with and the file it produced, so the change is documented rather than invisible.
The lossless mode strips metadata and repacks the file without touching a single pixel or sample. It saves less, and on a heavily scanned document it may not reach the limit at all — but when it does, the image data is bit-for-bit what it was. Your original is never modified either way; the output is always a new file.
Common questions
- Is C.D. California's limit the same as the state courts in Los Angeles?
- No. This page covers the U.S. District Court for the Central District of California, which uses CM/ECF at 35 MB per document. California Superior Courts use separate systems — commonly eFileCA — with their own per-document and per-envelope figures.
- Does 35 MB apply to each exhibit or to the whole filing?
- It is published as a per-document limit, so each uploaded PDF is measured separately.
- What compresses best in a court PDF?
- Scanned pages and photographs. Text, vector graphics, and form fields are already compact and change little. That is why a 30 MB brief with two photographs can often be halved by touching only the photographs.
- Does this tool upload my document anywhere?
- No. Compression runs inside your browser using WebAssembly. There is no server component to send a file to. You can disconnect from the internet after the page loads and it will still work.
The 35 MB figure on this page was last checked against the court’s own notice on Jul 2026. Limits change without much announcement — confirm it at the source before you file.