Drop the PDF and press the button. The tool works in three stages, cheapest first, and stops at the first one that gets the file under 300 KB.
Images are recompressed in place first, so text, links and forms stay exactly as they were. Only when a file still will not fit are the pages rebuilt as images, and even then an invisible text layer keeps the words searchable. A file already under the cap is handed back untouched. If your file is already small enough, you do not need this tool.
A one-page colour ID scan starts around 250 KB, so it arrives under this cap without being touched. That is the character of the 300 KB tier: most single pages simply fit, and the work only begins when a document runs to several pages or was scanned at a resolution nobody needed.
Where the 300 KB limit comes from
- Government job and recruitment portals300 KB per document
- Bank KYC and account opening300 KB per page
- Court and e-filing intake forms300 KB to 1 MB
- Insurance claim document uploads300 KB per attachment
- Tender and procurement submission portals300 to 500 KB
This is the most forgiving of the tight caps, which changes the advice. Rather than fighting for every kilobyte, the aim is to arrive under the limit with the page still worth reading, and that usually means deciding what the document is for before deciding how to scan it.
How the tool hits 300 KB
Add the PDF
Drop it or browse. It is read into browser memory; nothing is uploaded, so a slow connection makes no difference.
Stages one and two: tidy, then the images
Unused objects, thumbnails and stale metadata go first, which costs nothing at all. Then the pictures inside the file are recompressed in place, starting at 200 ppi, while your text, links and form fields are left exactly as they were.
Stage three, only when it is needed
If the images were not where the weight was, the pages are rebuilt as pictures with an invisible text layer behind them, so the words stay searchable. It probes at 150 dpi, works out the resolution that should fit, and will not go below 60 dpi.
Download, and read the result line
It shows the final size and which stage produced it. If none fitted, you still get the smallest attempt, labelled honestly, rather than a file that silently missed the target.
Structure, then the images in place, then the pages as pictures. It stops at the first stage that fits.
Untouched at the first two stages. If the pages do get rebuilt, an invisible text layer keeps them searchable.
The IDs, forms and statements people compress for portals never leave the device.
What fits in 300 KB, and what does not
The honest answer depends on page count and on what is on the pages. Text pages are cheap because a rendered page of black text compresses extremely well as a JPEG. Colour scans and photographs are expensive because every pixel carries information the encoder has to keep. The estimator uses typical figures to show which attempt your file is likely to land on.
When it cannot reach 300 KB
Some documents will not fit legibly, and the tool says so rather than pretending. When the result line reports a miss, three moves usually solve it:
- Split first. Use Split PDF to break the file into parts and compress each. Most portals accept several attachments even when each one is capped at 300 KB.
- Rescan the source. A fresh 150 dpi greyscale scan compresses far better than a colour scan that has already been through one compressor. Every pass costs quality, and the first pass should start from the cleanest source.
- Check the real limit. Portals sometimes state one number and accept another. Read the fine print, or try a slightly larger file before compressing harder than you need to.
Greyscale at high quality, or colour at low
At this size the real choice is between a greyscale page with plenty of resolution and a colour page with less. Both land under 300 KB. They are not equally useful, and which one wins depends entirely on what the reader needs to see.
- Colour matters where the colour is evidence: a stamp, a seal, a signature in blue ink that has to be distinguishable from a photocopy, a coloured security feature on an ID. Keep the colour and accept the softer image.
- Resolution matters where the page is dense: small print, a table of figures, a handwritten form, anything with a barcode or a reference number somebody has to read. Go greyscale and spend the budget on sharpness.
One practical test settles it. Open the compressed file at 100 percent and read the smallest thing on the page. If a reference number, a date or a signature is ambiguous, the trade went the wrong way. Run the original again with the other choice rather than compressing the output a second time, which only compounds the damage.
Where people use the 300 KB target
- Government job application documents1 to 3 pages, fits
- KYC document sets1 page each, fits in colour
- Court filing exhibits2 to 4 pages, fits in greyscale
- Insurance claim forms and photographs1 to 2 pages, borderline in colour
Why this runs in your browser
The files people compress for portals are the ones that identify them: passports, ID cards, certificates, bank statements, tax forms. Uploading them to a compression website in order to upload them again to the portal doubles the exposure for no benefit.
The tool is right above
Everything on this page runs in your browser. Scroll up, drop the file, and keep it on your machine.
Common questions
The questions people have with a 300 KB cap in front of them.
01What fits in 300 KB?
A single colour ID scan arrives around 250 KB and usually needs no work at all. Text documents of several pages fit easily. Multi-page colour scans are where it starts costing quality.
02Colour or greyscale at this size?
Colour when the colour is evidence, such as a stamp, seal or ink signature. Greyscale when the page is dense with small print or figures, because the saved budget buys sharpness.
03My file is already under 300 KB. Do I need this?
No. The tool checks first and hands a file that already fits straight back untouched. Send it as it is.
04Why do so many portals use 300 KB?
It is roughly the smallest cap at which one colour page stays legible, so it lets a portal accept colour documents without the storage cost of full-resolution scans.
05Will a scanned signature stay clear?
On a single page at 300 KB, yes. Across four pages sharing the same budget it may not, in which case split the document and upload the pages separately if the portal allows it.
06Will the text still be selectable?
Usually, yes. The first two stages leave the text exactly as it was. If the file only fits by rebuilding the pages as pictures, an invisible text layer goes behind them so the words can still be searched.
07Are my files uploaded anywhere?
No. Rendering and compression run in your browser. The file never leaves the device.
08Is it free?
Free. Every tool, unlimited use, no signup.