JPG to PDF under 400 KB
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.jpg.jpeg.png.heic.heif.webp.avif
- Files stay on your device
- Many images, one PDF
- No sign-up, no limits
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Room for a longer document: six to ten pages in one PDF below 400 KB, compressed on your device.
At 400 KB a PDF can carry a real document rather than a single proof: a full application form printout, six months of salary slips, a multi-page affidavit, a property tax receipt set, or a project report’s key pages. A few pages keep nearly their original sharpness; around ten typed pages stay comfortably readable. This page merges your images into one PDF, compresses them evenly to fit under 400 KB and tells you the exact result. Your files stay in the browser.
How to compress an image to 400 KB
- Add every page (select them all at once from the gallery), then drag into order and fix rotations.
- Pick A4 or Letter, and a 10 mm margin if the PDF will be printed and stapled; otherwise margin 0.
- Convert, check the final size and quality line, scroll through each page and download.
What happens to quality, size and metadata
Every page image is re-encoded as JPEG with one shared quality, chosen as high as 400,000 bytes allows; dimensions drop only if the lowest acceptable quality still doesn’t fit. For two or three pages that often means the maximum quality of 92 with no resizing, so the PDF may come out well below 400 KB. With many pages, each gets fewer bytes and fine print softens first. The final PDF is measured and never larger than 400,000 bytes, and photo metadata including GPS is removed.
Where 400 KB is asked for
Indian portals use 400 KB where one upload has to hold a complete set: state recruitment forms that ask for all educational certificates in one PDF, university admission and migration requests with several mark sheets, land and property services that want a sale deed or tax receipts, and bank or housing-loan applications with salary slips. Some court e-filing and grievance portals also cap annexures around 400 KB per file. Abroad, similar limits appear on some embassy and student-visa portals for financial documents. The cap is shown beside the upload field; when a form allows only one file, put pages in the order an officer would read them.
Tips for clear photos at small sizes
- Shoot every page under the same light and at the same distance, so all pages compress to the same clarity.
- Number the pages in the file name or the order you upload (main document, then annexures) to avoid confusion.
- Keep your original photos; if the office later asks for a sharper copy or a different limit, start again from them.
JPG vs PDF
| Full name | JPG | |
|---|---|---|
| Full name | JPEG (Joint Photographic Experts Group) | Portable Document Format |
| Introduced | 1992 | 1993 |
| Defined by | JPEG (ITU-T & ISO/IEC) · ITU-T T.81 / ISO/IEC 10918-1 | ISO · ISO 32000 |
| Compression | Lossy | Lossy or lossless |
| Transparency | No | Yes |
| Animation | No | — |
| Largest size | 65,535 × 65,535 px | 14,400 × 14,400 pt (200 × 200 in) per page |
| Chrome / Edge | Yes | Yes |
| Safari | Yes | Yes |
| Firefox | Yes | Yes |
| Windows | Yes | — |
| iPhone / iPad | Yes | — |
| Android | Yes | — |
| Typical use | Photos for sharing, email, online forms and printing, where it has to open everywhere. | Documents for sending, printing and uploading: forms, scans, invoices, applications. |
JPG JPG is the lossy photo format standardised in 1992 as ITU-T T.81. It throws away detail the eye barely notices, and the quality setting decides how much. It has no transparency and no animation, but every phone, computer, browser, printer and upload form opens it.
PDF PDF is a page-based document format created in 1993 and an open ISO standard (ISO 32000) since 2008. Each page keeps its exact layout, fonts and images, so it looks the same on every device. A PDF can hold scanned photos, text, vector drawings and forms.
Sources for this table
- www.itu.int/rec/T-REC-T.81
- www.w3.org/Graphics/JPEG/itu-t81.pdf
- developer.mozilla.org/en-US/docs/Web/Media/Guides/Formats/Image_types
- developer.android.com/media/platform/supported-formats
- www.iso.org/standard/51502.html
- www.iso.org/standard/75839.html
- www.rfc-editor.org/rfc/rfc8118
- www.loc.gov/preservation/digital/formats/fdd/fdd000474.shtml
Browser support data: caniuse.com, CC BY 4.0.
Without this site
You can make a PDF from photos without any site, but not at a chosen size. iPhone: Files › select images › More › Create PDF. Android: open the images in the gallery, Print › Save as PDF. Windows: right-click the images › Print › “Microsoft Print to PDF”. Each keeps the original photos, so ten pages typically come to 15–30 MB. A Mac’s Preview Quartz filter “Reduce File Size” shrinks heavily but without a target.
Troubleshooting
- The phone slows down with 30 photos. Close other apps and tabs, or make two PDFs of 15 pages if the form accepts more than one file.
- Some pages are photos of photos. Glossy prints reflect light. Tilt the camera a little to avoid the glare spot.
- The form actually wants 500 KB or more. Then use JPG to PDF under 500 KB, which leaves each page more detail.
Questions and answers
How do I convert JPG to PDF under 400 KB?
Add the JPGs here, put them in order and press Convert. You get one PDF where every page is compressed to the same quality so the total stays under 400,000 bytes. The result line shows the size and quality. Since everything runs in your browser, the pages are never uploaded to a server.
Is 400 KB enough for ten pages?
Usually, for typed documents photographed clearly: ten A4 pages at 400 KB remain readable on screen and when printed. Handwritten pages, coloured forms and pages with photos need more space each. If the pages won’t fit at a readable quality, the converter stops and shows the smallest size it reached.
Why is my PDF much smaller than 400 KB?
Because the pictures didn’t need more. If a few small photos fit at the maximum quality of 92, the converter doesn’t inflate the file to reach 400 KB. Forms check the upper limit; if yours also has a minimum, use JPG to PDF, which keeps the original images.
Can I use iPhone HEIC photos for a 400 KB PDF?
Yes. HEIC is decoded in the browser and placed into the PDF as JPEG, the same as a JPG. In Safari, tap the box, choose Photo Library and select all the pages at once. They are processed on the iPhone itself, so nothing goes to a server.