Exact 300 kB target · Free · No upload
Compress PDF to 300kB
Our largest preset and the ceiling NTA bulletins set for PDF uploads: certificates, marksheets, address proof and short reports land at or just under 300 kB without leaving your device.
Files never leave your device — compression runs in your browser.
Drop your PDF here
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PDF · up to 100 MB · any number of pages
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Processing on your device — large PDFs can take a minute.
Need a photo at this size instead? Compress an image to 300 kB .
Step by step
How to compress PDF to 300kB?
Works on phones, tablets and computers — no account needed.
- 1
Upload the PDF
Drop your PDF into the box above or click to browse. Scanned documents, forms, certificates and multi-page reports all work. The file stays on your device.
- 2
Confirm the target size
The target is pre-set to 300 kB here. You can change the number, switch the unit to MB or a percentage, and tick black & white for scanned pages that do not need colour.
- 3
Compress and download
We try a lossless clean-up first and only re-render pages when the file is still too big. Compare the first page before and after, then press Download.
Where this size shows up
Where a 300 kB PDF is typically required
Of all our PDF presets, 300 kB is the one with the most official backing. The NTA Information Bulletin for NEET (UG) 2026 asks for the category certificate, the Class X certificate, the Class X marksheet, the address proof and the PwBD or UDID certificate as separate PDFs, each between 50 kB and 300 kB. The JEE (Main) 2026 bulletin uses the same 50–300 kB band for the Class 10 certificate or marksheet and for the disability certificate. If you need to compress a PDF to 300 kB, it is very likely for one of these uploads, and this page opens with that target already filled in.
Three hundred kilobytes is also a comfortable budget rather than a squeeze. A single scanned page fits with quality to spare, a three-page form fits at the full 150 dpi, and a text-only report of ten pages or more often gets through the lossless route with its text still selectable. That makes 300 kB a sensible default for anything that will be read on a phone: a two-page CV for a careers site, a signed rental agreement, a bank statement for KYC, or a short project report sent over mobile data.
Not every portal publishes a figure. The GATE 2026 required-documents page from IIT Guwahati asks for category, PwD and dyslexia certificates in PDF format and warns that unreadable uploads can delay or sink an application, but it states no kilobyte cap at all. When a form says nothing, 300 kB is still a good ceiling: it uploads in seconds on a weak connection, slips past attachment filters, and keeps a scan legible when the reviewer zooms in on a stamp.
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NEET (UG) document uploads
Category certificate, Class X certificate, Class X marksheet, address proof and PwBD/UDID certificate, each as its own PDF between 50 kB and 300 kB.
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JEE (Main) certificates
The Class 10 certificate or marksheet and the disability/UDID certificate, uploaded as PDFs in the same 50–300 kB band.
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Two-page CV for a careers site
A CV exported from Word or Canva with a photo and icons. When the file is mostly text, the lossless pass keeps the layout, fonts and links intact under 300 kB.
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Bank statement or address proof for KYC
Two or three scanned pages in black & white fit comfortably, with account numbers, dates and stamps still readable.
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Short reports and signed agreements by email
A ten-page digital document sent to someone on mobile data: it opens at once and never trips an attachment limit.
Reference
Portals with PDF limits around 300 kB
Typical limits from official notifications and help pages. Each row links to its source.
| Portal / purpose | Item | Size limit | Format | Source |
|---|---|---|---|---|
| NEET (UG) 2026 – NTA | Category certificate Information Bulletin 2026, upload specifications; check the current year's bulletin | 50–300 kB | Official | |
| NEET (UG) 2026 – NTA | Class X certificate and Class X marksheet Separate files; a CGPA conversion certificate has the same band | 50–300 kB each | Official | |
| NEET (UG) 2026 – NTA | Address proof (present and permanent) | 50–300 kB | Official | |
| NEET (UG) 2026 – NTA | PwD / PwBD / UDID certificate | 50–300 kB | Official | |
| JEE (Main) 2026 – NTA | Class 10 certificate or marksheet Information Bulletin 2026; check the bulletin for the session you apply to | 50–300 kB | Official | |
| JEE (Main) 2026 – NTA | Disability / UDID certificate | 50–300 kB | Official | |
| GATE 2026 – IIT Guwahati | Category (SC/ST), PwD/UDID and dyslexia certificates Must be clear and readable; unreadable uploads can delay or reject the application | No cap stated | Official |
Limits change between recruitment cycles. Always confirm the numbers on the notification or form you are filling in before you upload.
Pro tips
Tips to reach 300 kB without losing readability
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Work out the per-page budget first
Divide 300 kB by the page count before you scan. One page gets the whole budget, three pages get about 95 kB each and ten pages about 28 kB each once a little file overhead is set aside. Four or five scanned pages are comfortable in colour; beyond that, switch to black & white or split the document so each part has its own 300 kB.
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Scan at 150–200 dpi, not 600
The re-render method draws pages at up to 150 dpi, so a 600 dpi scan only adds bytes the tool has to throw away. Set the scanner or scanning app to 150–200 dpi and A4, and the source file arrives smaller and compresses in fewer passes. A straight phone photo of a page is often several megabytes; a scanning app's document mode crops and flattens it first.
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Tick black & white for marksheets and certificates
Marksheets and government certificates sit on a tinted security background that costs more bytes than the text printed over it. Converting to grayscale removes that cost, and a 300 kB budget then has room for even a dense, small-print marksheet at full resolution. Leave colour on only if the portal asks for a colour copy or a coloured stamp carries meaning.
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Compress each document separately
NEET and JEE Main want the certificate and the marksheet as separate uploads, each with its own 50–300 kB band, so do not merge them into one PDF and then fight for space. Run each file on its own: a one-page certificate will usually land well under the cap at a high quality setting, and a merged file would have to be split again anyway.
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Mind the 50 kB floor
NTA bulletins set a minimum as well as a maximum. If a one-page certificate already weighs 180 kB, leave it alone: the tool reports that the file is already under 300 kB and offers the original untouched. Pushing it down to 20 or 30 kB on our 20 kB or 50 kB preset would drop it below the portal's lower limit.
Quality check
What to expect at 300 kB
A one-page scan at 300 kB looks the same as the original on screen. An A4 page rendered at 150 dpi is 1240 × 1754 pixels, and 300 kB is enough to store that as a JPEG at a high quality setting, so seals, signatures, small print and the serial number along the edge stay crisp. Colour can usually stay on. A scan has no real text layer to begin with, so the switch to the re-render method takes nothing away that you had before.
A three-page form behaves in one of two ways. If you filled it in digitally and exported it, the lossless pass frequently brings it under 300 kB on its own, and your typed answers, links and form fields survive untouched. If it was printed, signed and scanned, the tool re-renders it with roughly 95 kB per page, which still allows the full 150 dpi and readable handwriting; tick black & white if the pages were photographed under uneven light.
A ten-page report is where the two methods part company. A Word or Google Docs export that is mostly text often passes through the lossless route and keeps selectable, searchable text. One full of photographs and charts will be re-rendered with about 28 kB per page: body text stays readable, but photos soften and the smallest chart labels may blur. If that matters, raise the target, drop a few images before exporting, or split the report. Expect the result panel to show a figure such as 291 kB rather than 300, because the search stops at the first size that fits.
Good to know
Frequently Asked Questions
Will text stay sharp when a PDF is compressed to 300 kB?
For most documents, yes. A single page or a short form has far more budget than it needs at 300 kB, so text rendered at 150 dpi stays sharp, down to the footnotes on a marksheet. Text suffers only in a long, image-heavy document that has to be re-rendered: ten pages share the 300 kB, each gets under 30 kB, and JPEG artefacts begin to show around small letters. The first-page preview in the result panel shows exactly what you are getting before you download, and the note beneath it says which method ran.
Can a multi-page PDF fit into 300 kB?
Yes, and 300 kB is the preset where multi-page files are most comfortable. Four or five scanned pages in colour, eight to ten in black & white, or a text-only digital document of twenty pages or more are realistic. All pages draw on one budget, lighter pages hand their spare bytes to busier ones, and the tool makes up to three passes to get under the line. If it still cannot reach 300 kB it says so plainly and suggests black & white, a larger target such as 350 kB, or splitting the file into two uploads.
Why is the result 290-something kB and not exactly 300 kB?
Two reasons, both deliberate. We count 1 kB as 1,000 bytes, and the quality search stops at the first setting that fits, so the file settles a little below the line rather than on it. That margin protects you on a portal that counts 1,024 bytes per kB, or that checks the size after its own processing. A file that is 300,400 bytes could be refused by an upload box with a 300 kB rule; one at 292 kB passes every reading of the rule.
My scanned certificate is already under 300 kB. Should I still run it through?
Only if you want it smaller for a different reason. When a file is already at or below the target the tool tells you so and hands back the original unchanged, so checking costs nothing. Bear in mind that NEET (UG) and JEE (Main) also set a floor of 50 kB for these PDFs: a certificate squeezed to 25 kB would be too small for the portal. If you need a smaller cap for another form, use the 200 kB or 100 kB preset rather than chasing the lowest number possible.
Do you store my PDFs?
We cannot store what we never receive. Because the whole process happens in your browser, no copy of your document, its pages or its text is written to our servers, and there is no account history tying files to you. The compressed PDF lands in your Downloads folder and nowhere else. Our hosting provider keeps standard server logs for page requests, which record things like IP address and browser type but never file contents. We also run no database. For a plain-language description of what little data the site does handle, see our privacy policy.
What is Mb2KbSizer and what does it do?
Mb2KbSizer shrinks images and PDF documents to a size you choose, free of charge, without leaving your browser. Give the PDF compressor a file of up to 100 MB, enter a target in kB, MB or as a percentage of the original, and it works to bring the document under that figure. Typical jobs include getting a scanned marksheet below a portal's cap, squeezing a multi-page application form into an email, or lightening a report before sharing it. The same site offers an [image compressor](/) and a bulk image compressor, both built on the same no-upload approach.
Is Mb2KbSizer free to use?
It is, with no catches. You will not meet a paywall after the first file, a cap on pages, a size restriction beyond the 100 MB input limit, or a stamp on the output. We do not ask for an email address or an account. Ads on the page cover our hosting bill, and since your device does the processing, we have no per-file costs to pass on. Whether you compress one certificate or every document for a job application, the price is the same: nothing. There is no paid plan waiting behind the free one.
Do I need to install any app to use Mb2KbSizer?
There is nothing to install. The PDF compressor is a normal web page that loads its compression code (Mozilla's pdf.js and pdf-lib) into the browser and runs it there. Any current version of Chrome, Edge, Firefox, Safari or Samsung Internet will do, on Android, iPhone, Windows, macOS or Linux. You can pin the page to your home screen through your browser's Add to Home Screen option if you like a one-tap icon, but it still fetches the page over the internet each time, so it is not an offline app. We publish nothing in any app store, and no software needs updating.
How do I compress a PDF using Mb2KbSizer?
Start by dropping your PDF into the upload box or tapping browse to select it; the tool opens the file on your device. Next, check the Target Size field. On a preset page the number is already filled in, but you can change it and switch the unit between kB, MB and %. Tick black & white if the file is a scan and you want extra savings. Then press the compress button. The result panel shows the first page before and after, the new size, the percentage saved, the page count and which method was used. Press Download to save the file.
What formats does Mb2KbSizer support?
This tool accepts PDF files only, up to 100 MB and with any number of pages. It cannot open a password-protected PDF; remove the password in the program that created it, then try again. Word, Excel or image files need converting to PDF first, which most phones and computers can do through Print to PDF or Save as PDF. The output is always a standard PDF with the original page sizes. If you want to shrink photos rather than documents, use the [image compressor](/), which handles JPG, PNG, WebP, GIF, BMP, AVIF and HEIC where the browser can decode it.
Is it safe to upload my PDFs to Mb2KbSizer?
Your PDF is never sent anywhere, so there is no upload to worry about. The browser opens the file locally, and both compression methods run on your own processor: the lossless pass re-saves the document with compressed streams, and the re-render pass draws each page and packs it into a fresh PDF, all in memory on your device. Our servers only deliver the page itself. This matters for the kind of documents people compress: ID scans, bank statements, offer letters, medical reports. They remain as private after compression as they were before you opened the tool.
Have a photo to shrink too?
Our image compressor lands JPG, PNG and WebP files at an exact kB size — handy when the same form needs a photo and a PDF.