File upload limits before submitting images documents or identity scans

Checking File Size Limits Before Uploading Documents

Most upload pages display a maximum file size — “Max 5 MB,” “10 MB limit,” or “File must be under 2 MB.” Check that label before selecting a document. Doing this first generally avoids a failed upload after you’ve already picked and prepared the file from your device. When the limit isn’t visible directly on the upload page, look under a help or FAQ section, where document requirements are commonly listed.

Knowing the size limit up front lets you adjust the scan resolution or file format before you start, rather than having to go back and redo a scan later in the process.

Matching File Formats to Accepted Types

Accepted formats are also generally listed on the upload page, typically PDF, JPG, PNG, or TIFF. Saving in the wrong format tends to cause rejection even if the file size is comfortably under the limit. Getting the format right ahead of time is usually the easier fix — check before you scan or save the document rather than after. If the format list isn’t shown or is unclear on the upload screen, looking at example file names or a demo upload link, where available, can offer a hint.

Signed documents often call for PDF specifically, while a photo ID upload more commonly asks for JPG, though this varies by service and is worth confirming rather than assumed. Sorting out the format ahead of time helps you avoid a last-minute conversion that can degrade image quality right when it matters most.

Adjusting File Size When the Limit Is Low

When a document or scan exceeds the size limit, there are a few practical ways to reduce it without losing readability. For a scanned document, lowering the scan resolution to around 150–200 DPI instead of 300 DPI is a common approach — though it’s worth knowing that some services, particularly identity verification or document-processing systems that rely on automated text recognition, may specify their own minimum resolution for a scan to remain legible to their system even if it looks fine to a human eye, so checking whether a minimum DPI is stated anywhere in that service’s requirements is worth doing before going too low.

A detail that’s easy to overlook: if the original is a plain text document rather than a photo, saving or scanning it in grayscale rather than full color can shrink the file size considerably, often without any real loss of readability, since color information takes up meaningfully more data than a document only needs to display black text on a white background. For a photo of an ID card specifically, using a compression tool or adjusting the JPG quality setting downward is generally the more relevant option instead, since ID photos usually do need to preserve color and fine detail. Testing one adjustment at a time and checking the resulting file size before uploading is a more reliable way to land in the right range than guessing at several changes at once.

Avoid resizing an image down to very small dimensions, since the text on the document can become unreadable well before the file size drops to where you need it. The goal is staying under the limit while keeping names, numbers, and barcodes clearly legible. Most services reject files that come out too blurry or illegible after compression, so it’s worth keeping a genuinely readable version even after reducing the file size, rather than optimizing purely for the smallest possible file.

Checking File Names and Page Count Before Submitting

Some upload systems reject files with special characters, unusually long names, or spaces in the file name, though this varies by service. Before uploading, renaming the document using only letters, numbers, hyphens, or underscores is a reasonably safe default. A clean file name such as “Passport_Scan.pdf” tends to be safer than one with symbols or extra spaces. Checking the page count before uploading matters if the service accepts multi-page documents.

A single PDF should generally contain all required pages in the correct order. Uploading a file with missing pages or extra blank pages can cause a processing delay, or in some cases an outright rejection, depending on how strictly the service checks submitted documents. Reviewing the document on your device before submitting it is worth the extra minute it takes.

FAQ

Question: What should I do if the upload page does not show a file size limit?

Answer: Look under the help section, FAQ, or instructions area, since the limit is often listed there even when it’s not shown directly on the upload screen. When none of these clearly state a maximum, starting with a file under 5 MB in PDF or JPG format is a reasonably safe default, since that size tends to work for most official upload systems, though it’s not a universal guarantee.

Question: Can I upload a scanned ID in PNG instead of JPG?

Answer: Only if the accepted formats list explicitly includes PNG. Many identity verification services accept JPG or PDF specifically but not PNG, though this differs between services, so checking the format list on the upload page before saving your scan is the more reliable approach than assuming PNG will work.

Question: What happens if my file is still too large after compressing the image?

Answer: Lowering the scan resolution further, converting to grayscale if the document is text-only, or cropping any empty margin space around the document are worth trying next. If the file is still over the limit after that, splitting the document into separate files is worth considering if the service allows multiple uploads for a single submission.