Reduce an image or PDF below a 300KB limit

Check whether the upload field expects an image or a PDF

A 300KB limit can appear beside very different tasks. One field might expect a portrait image; another might expect a document scan in PDF. Do not choose the format solely on the basis of which one happens to create the smallest download. The receiving instruction determines what kind of file belongs there.

For example, India's published e-Visa instructions give the passport bio-page PDF a separate size range from the portrait JPEG. The number alone does not make those two attachments interchangeable. Use the dedicated guide for that workflow and check its minimum as well as its maximum. This general tool is not an automatic approval check for any named application.

The exact ceiling is 300,000 bytes

This new preset uses decimal KB and requires the output to be smaller than 300,000 bytes. A 300KiB calculation produces a different ceiling of 307,200 bytes. A result that fits that larger binary allowance can exceed a receiving system's decimal 300KB cap.

Read the measured size of the download rather than inferring it from a rounded label. A website may allow equality at its own maximum, while this tool's under-target condition is deliberately strict. If the receiving form gives a precise byte figure, the compatibility checker can compare against that number directly with the units made explicit.

Prepare a clean, complete document capture

For a photographed page, check the whole relevant area before using any size tool. The corners, headings and small printed characters should be visible. A file can become much smaller when reduced, but missing content cannot be recovered from a frame that never included it.

Avoid unnecessary surrounding desk space when an appropriate crop is permitted, without removing context that the recipient needs. This page does not provide a crop editor or identify document edges automatically. Prepare the source using a suitable authorised workflow, retain that original and then test a separate copy against the byte limit.

How a supported image is reduced

The image engine decodes supported input, re-encodes it locally and may reduce pixel dimensions as it searches for the target. It checks the resulting format and bytes before offering a download. A success result means the declared size condition passed, not that the image stayed visually identical.

Check the final width and height when the upload instructions specify a minimum. A document page needs enough pixels for its printed detail, while a photograph may have a particular dimension range. Do not assume that the engine understands the destination's rules simply because it knows the size target on this page.

What to expect from a PDF compression attempt

PDF handling is limited to lossless repacking rather than silently replacing pages with lower-resolution images. It can remove storage overhead in some files, but a scan-heavy PDF may already store its image data efficiently. Repeating the same repack does not guarantee another reduction.

If the required PDF cannot fit, look for a better original export or scan while preserving the evidence. Do not remove pages, discard needed annotations or flatten a signed form purely to get a smaller result. Some documents cannot meet a tight allowance through the available methods; an honest failure is more useful than a download that conceals damage or exceeds the promised ceiling.

A format conversion may need its own size check

If a receiving service rejects HEIC or WebP, use a real converter to create an accepted format where appropriate. Renaming the source does not change its contents. After conversion, measure the new file because its bytes can differ considerably from the original's size.

An input that is already below this target may be returned unchanged. That means its format stays unchanged too. A small HEIC is still not a JPEG, and a small PNG is not a PDF. Use the compatibility checker to compare the final type as well as its size, rather than relying on the word 'compressed' to imply every upload problem was solved.

Inspect the details that a thumbnail can hide

Read the saved output at a useful size. For a document, examine dates, reference numbers, stamps and fine print. For artwork, look at thin lines and small text. Compression artefacts or reduced dimensions can look harmless in a tiny preview but matter when someone needs to understand the file.

Pay attention to transparency when a conversion produces JPEG. Choose a background deliberately and compare the result with the intended appearance. White artwork can disappear on white, and a black fill can change the meaning of a transparent design. A colour choice is not a tool for removing the original photographed background.

Use the output safely in the receiving service

Make My Files Work processes supported files on your device in the browser. It does not attach them to the receiving account. Once you have checked the download, return to that account, select the correct version and complete its upload and confirmation steps. Keep the source file in case a clearer or differently formatted copy is requested.

The input limit is 25MiB per file, with further pixel and PDF-page safeguards. Unreadable, encrypted or unsupported inputs may be refused before compression. The tool also stops when the target is not attainable through its bounded attempts. Neither a local success nor an output preview is a guarantee of acceptance, authenticity or suitability for an official application.

Questions that come up