Upload portals often ask for documents as pictures: a certificate for a job, exam or government application, a proof of address, a payslip, a receipt for an expense claim. And they often cap each file at 100 KB. A photo of a page from a phone can be thirty times that.
This page is set up to resize an image to 100 KB, which here means its file size, not its shape. Target size is already set, so the tool finds the best quality that fits. The trick with documents is different from photos: what matters is that every word stays readable. Below is how to get there, which format to use, and what to do with several pages.
Documents that often need to be under 100 KB
Any page you scan or photograph becomes a picture, and a picture can be compressed. Typical cases are:
- You need to upload a certificate, a mark sheet or a reference for an application.
- A bank, landlord or insurer asks for a proof of address or a copy of an ID card.
- An expenses system wants a picture of each receipt.
- A support form or a claim asks for a photo of a letter or a label.
100 KB is enough for a full page of normal print, as long as the picture is not much bigger in pixels than it needs to be. A scanned document from a flatbed scanner and a phone photo of the same page compress quite differently, and both are covered below.
How to compress an image to 100 KB
- Press Select images and choose the scan or photo. Select several to do a set of pages.
- Check that Compress by shows Target size, set to 100 KB.
- Under Format, keep Original, or pick JPG if the portal asks for it. To compress a JPG to 100 KB, Original keeps it a JPG.
- Press 100% under the picture and look at the smallest print in the split view.
- Read the Result line, for example JPG · 1500 × 2000 · 97 KB · 96% smaller, then press Compress and save.
The tool tries up to 8 quality levels and keeps the highest one under 100 KB. If even the lowest is too big, Allow a smaller picture size makes the page smaller in pixels and tries again, in up to 3 rounds. A KB here is 1,000 bytes, so the result also passes a portal that counts 1,024 bytes per KB.
Keep the text readable
Text is where compression shows first. The sharp edge between black letters and white paper is hard to describe in few bytes, so at low quality letters grow a faint haze and thin strokes break up. Readable text needs enough pixels per letter and a quality that keeps the edges.
Crop and straighten first
A phone photo of a page usually includes the table, a hand or a shadow. Cut it all away with Crop image, so the 100 KB goes on the page itself. If the page is on its side or upside down, turn it with Rotate image first.
Choose the size in pixels yourself
A phone photo of a page can be 4000 pixels tall, far more than normal print needs. Switch on Also make it smaller in pixels and set the Longest side to about 2000. On an A4 page, that is around 170 pixels per inch, which keeps normal print clear, and it leaves the tool room for a higher quality.
For very small print, such as the terms on a receipt, try 2400. For a page of large type, 1600 is often enough. Check the smallest words at 100% each time. If you compress an image to 100 KB and the words still look soft at 2000, the page probably has heavy shading: better light helps more than fewer pixels.
Light and contrast
Photograph the page in even daylight, flat on a table, with no shadow from your phone. A clean white background compresses to almost nothing, while grey shading and paper texture cost bytes and blur the letters.
JPG or PNG for a scanned document?
Most portals ask for JPG, and for photos of documents that is the right choice. But a clean scan of black text on white paper can be smaller and sharper as a PNG with fewer colours. If the portal accepts PNG, try both.
| Your page | Try | Why |
|---|---|---|
| A phone photo of a page, with shading | JPG | Copes well with soft shading and paper texture |
| A colour certificate with a stamp, a seal or a photo | JPG | Keeps the colours and the photo smooth |
| A clean scan of black text on white | PNG | Few colours, so the text stays crisp and the file small |
| A screenshot of a statement or an email | PNG | Flat colours and sharp text, which PNG keeps exactly |
With Format on PNG and Target size on, the tool tries the page as it is first, then with fewer and fewer colours, before making it smaller in pixels. The Compress PNG page explains the colour choices.
Several pages, and documents that are PDFs
For a document of several pages, select them all at once: up to 100 per run. Each page gets the same 100 KB target and is compressed in turn, and Save all as ZIP saves them together. Each file keeps its own name with _compressed on the end, so the order is easy to keep if your pages are numbered.
On the done screen, a page that could not reach 100 KB still gets the closest result, and its row says Could not reach 100 KB in red. Crop that page tighter, or give it a smaller Longest side, and run it again.
This page works on pictures. If your document is already a PDF, use Compress PDF instead. If the portal wants a picture rather than a PDF, convert the PDF to JPG first, then compress the JPG here.
Documents are personal. Here, they are compressed inside your browser and are never uploaded to us, and the compressed pictures carry no camera, date or location details. Read more on the privacy page.
Get your document under 100 KB now
To compress an image to 100 KB with readable text, crop to the page, set a Longest side of about 2000 pixels, and let Target size find the best quality that fits. Check the smallest print at 100% before you save.
Select your scans above and press Compress. It is free, and your documents stay on your device.
