"Photograph: JPG, maximum 50 KB, 200 × 230 pixels." It's a familiar line on government forms, university applications, job portals and exam registrations. Your phone photo is 3.8 MB — about 76 times too big.
The usual confusion is between two different things: image dimensions (pixels) and file size (kilobytes). You can change one without the other, and the right fix usually combines both. This guide explains the difference, then gives you settings for each common limit, step by step.
- Dimensions (pixels) and size (KB) are different. Most of the reduction comes from fewer pixels.
- Use Compress image: set max width and quality, output JPG.
- If exact dimensions are required, use Resize image first, then compress.
- A 600 px-wide photo at 60% quality is usually under 100 KB.
- Never enlarge a small photo — it doesn't add sharpness.
Dimensions vs size: the difference that solves half the problem
Dimensions are width × height in pixels, e.g. 4000 × 3000. That's what a portal means by "200 × 230 pixels".
Size is how much space the file takes, in KB or MB. That's what "under 50 KB" means.
More pixels means more data. A 4000 × 3000 image has 12 million pixels; 600 × 800 has under half a million — about 25 times fewer. So reducing dimensions is the most powerful way to reduce size, and quality settings then fine-tune it.
Size also depends on content: a photo with a plain white background compresses far better than a dense tree canopy at the same dimensions, because detail costs data.
What "quality" means in JPEG
JPEG compresses lossily: it splits the image into small blocks and discards fine detail the eye struggles to notice. The quality setting controls how much is discarded:
| Quality | Visible effect | Use |
|---|---|---|
| 80% | Practically identical to the original | Archiving, general sharing |
| 60% | Slight difference at heavy zoom | Uploads — usually the best balance |
| 40% | Noticeable blockiness around edges and text | Very tight limits only |
Tip: reducing dimensions before lowering quality gives cleaner results. A 600 px image at 60% usually looks better than a 1600 px image at 25% at the same file size.
The core method: Compress image
- Open Compress image. The image is processed in your browser, not uploaded.
- Choose one or more images.
- Quality: start with "medium (60%)".
- Max width: 800 px for portraits and signatures, 1280 px for photographed documents.
- Output format: JPG — the most widely accepted for uploads. WebP is smaller, but many portals don't accept it.
- Compress and compare the size.
- Still too big? Lower max width or quality and try again from the original.
When exact pixel dimensions are required
Some portals demand exact dimensions, like 200 × 230 or 600 × 600. Use Resize image:
- Choose the image.
- Enter the required width and leave height blank to keep proportions — or enter both and choose "match exact size" if the portal is strict (this can stretch the image if proportions differ).
- Download, then compress with Compress image if it's still too big.
To avoid distortion: crop the photo to the required aspect ratio first in your phone's editor (200 × 230 is close to 7:8), then resize.
Suggested settings for common limits
Starting points that work for most portraits and documents — adjust slightly for your image:
| Required limit | Max width | Quality | Note |
|---|---|---|---|
| 20 KB (signature) | 300–400 px | 60% | A plain white background helps a lot |
| 50 KB (portrait) | 400–600 px | 60% | Crop to head and shoulders |
| 100 KB | 600–800 px | 60% | A very clear portrait |
| 200 KB (photographed document) | 1000–1280 px | 60% | Grayscale helps for text |
| 500 KB | 1600–1920 px | 80% | Excellent for most uses |
| 1 MB | Up to 2500 px | 80% | Close to the original |
Special cases
Signature images
Signatures need contrast, not colour. Sign with a thick black pen on white paper, photograph in good light, and crop tightly. A pure white background keeps the file tiny. If the background looks grey, raise brightness and contrast in your phone editor before compressing.
Official passport-style photos
Official bodies usually require a plain light background, a clear face and a specific face-to-frame ratio. Read the rules carefully, and don't compress so hard that facial features turn blocky. 50 KB at 400–600 px wide usually gives a very clear photo.
Screenshots with text
Screenshots are usually PNG and large. Convert to JPG at 70–80% — low quality smears letters quickly — or keep PNG for tiny text and reduce dimensions only. Use PNG to JPG.
HEIC or WebP images
Convert to JPG first: iPhone HEIC photos and WebP images saved from websites are rejected by many sites. Use Convert image or WebP to JPG. To understand the formats, read JPG vs PNG vs WebP.
A document that must be uploaded as an image
If the portal accepts a JPG of your certificate instead of a PDF, scan it with your phone's document scanner in grayscale, then compress at 1200 px wide and 60%. If the certificate is already a PDF, turn the page into an image with PDF to JPG, then compress it.
Why does my phone show a different size than the portal?
- 1,000 or 1,024? Some systems count a kilobyte as 1,000 bytes, others 1,024. A "50 KB" photo on your phone may be 51,200 bytes — over 50,000. Leave a margin: aim for 45 KB on a 50 KB limit.
- Hidden metadata: phone photos carry EXIF data (location, device) adding kilobytes. Compression tools usually strip it on re-save.
- Previews mislead: the gallery may show the original's size, not your edited copy. Check the file size after download in your Files app.
Common mistakes
Enlarging a small photo. If the portal wants 600 × 600 and your photo is 300 × 300, upscaling adds blur, not detail. Take a new photo at sufficient resolution.
Repeated compression. Each JPEG pass adds artefacts. Start from the original every time.
Renaming the extension. Renaming photo.png to photo.jpg doesn't change the format; portals may detect it and reject the file. Use a real converter.
Skipping the crop. A portrait showing the whole room wastes bytes on worthless detail. Crop around the face first.
Going far below the limit. If the limit is 100 KB, there's no need to go down to 20. Aim near the limit with a small margin for the best possible clarity.
Complete workflow: a 50 KB, 200 × 230 portrait
- Shoot: against a light wall, with daylight from the front, phone at eye level.
- Crop: in your photo editor, crop to roughly 200:230 with head and shoulders.
- Resize: Resize image to width 200, height 230, "match exact size" (the ratio already matches after cropping).
- Compress: Compress image at 80%, JPG. At these small dimensions the result is usually a few dozen KB.
- Check: confirm dimensions and size in your Files app, then upload.
Common form requirements and how to meet them
| Requirement | Meaning | How |
|---|---|---|
| "JPG only" | No PNG, HEIC or WebP | Convert with Convert image |
| "200 × 230 pixels" | Exact dimensions | Crop to ratio → Resize image |
| "20–50 KB" | Minimum and maximum | Aim for ~40 KB; if under 20, raise quality |
| "White background" | For portraits | Shoot against a white wall with even light |
| "Signature in black ink" | High contrast | Black pen on white paper, boost contrast |
| "Recent photograph" | Within a few months | Don't reuse old photos |
A minimum size? Yes — some portals require at least, say, 20 KB to ensure clarity. If yours is smaller, raise quality to 80% or increase dimensions slightly from the original.
Batch-processing images
For an online store, a website or a set of documents:
- Put all images in one folder.
- Open Compress image and select them all.
- Apply one setting — e.g. max width 1280, quality 60%, JPG or WebP.
- Download and spot-check one or two before using them all.
For websites, WebP gives smaller files at the same quality, which speeds up page loads.
On your phone
All of this works in a mobile browser:
- iPhone: when picking from the Photo Library, iOS may offer a size option — Actual, Large, Medium, Small. Choose "Actual" and let the tool do the shrinking.
- Android: pick from Files or Gallery; results go to Download.
- Built-in editors: use them to crop, then resize and compress with the tools — phone editors don't usually show file size in KB.
Signatures and photos on exam and visa forms: extra tips
Forms for exams, visas and government services are strict, and rejections are common. A few extra checks:
- Look at the sample image many portals provide, and match its framing.
- Check orientation: a sideways photo usually means EXIF rotation wasn't applied; re-save it after rotating in your editor.
- Avoid filters and beauty modes — official photos must be unedited apart from cropping and resizing.
- Keep both a full-resolution original and the compressed version — you may need different sizes for different forms.
- Re-upload rather than resubmit if the portal offers a preview and the image looks wrong.
Quick reference: from phone photo to upload-ready
- Take the photo in good, even light against a plain background.
- Crop in your phone editor to the required aspect ratio.
- Resize with Resize image to the required pixel dimensions.
- Compress with Compress image — JPG, 60–80% quality.
- Check the final size in your Files app, leaving a small margin under the limit.
- Upload, and screenshot the confirmation page.
FAQ
How do I get an image under 100 KB without losing clarity?
Reduce width to 600–800 px, then use 60% quality. That's usually enough for a very clear image on screen.
What's the difference between compressing and resizing?
Resizing reduces the number of pixels (dimensions). Compressing reduces the data needed to store those pixels (quality). Best results come from both.
Is WebP better than JPG?
WebP is usually smaller at the same quality, but many government and university portals don't accept it yet. Use JPG for official uploads and WebP for websites.
Can I shrink several images at once?
Yes — select multiple images in Compress image and the same settings apply to all.
Are my photos safe?
Yes. Compression and resizing happen in your browser; images are never sent to a server. See our security page.
The portal asks for "300 DPI" — what does that mean?
DPI is print metadata; it doesn't change the image on screen. What matters is pixel dimensions: 600 × 600 px prints at 2 × 2 inches at 300 DPI. If a portal insists on a DPI value stored in the file, you may need an image editor to set it.
Bottom line
Hitting a KB limit starts with understanding dimensions vs size: reduce pixels first, then tune quality, use JPG for portals, and leave a small margin under the limit. For exact dimensions, crop, resize, then compress.
Start now with Compress image or Resize image — free, and your photos never leave your device.