Resize Image to 20KB

Compress a photo or signature to 20 KB or less for SSC, IBPS, UPSC or NEET forms. Exact pixel presets, auto quality search, instant JPG download.

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Click or drop a JPG, PNG or WEBP image
Processed on your device. Output is always a JPG under your size limit.
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What is "resize image to 20KB"?

Online application forms for Indian recruitment and entrance exams – SSC, UPSC, IBPS and other banking exams, NEET, state PSCs and many more – ask you to upload a photograph and a signature that are below a strict file-size limit, often somewhere between 10 KB and 50 KB, and sometimes also at a fixed pixel size. A phone photo is usually 2–5 MB, so it is rejected. This MavexTech tool resizes and compresses your image to 20 KB or less (or any limit you type), optionally at an exact pixel size, and gives you a JPG that is guaranteed to be under the limit you set. Everything happens in your browser: your photo and signature are never uploaded.

How to resize a photo or signature to 20KB

  1. Check your exam notification for the exact rules: maximum and minimum KB, pixel or centimetre size, and file format (almost always JPG/JPEG).
  2. Choose your image. Click the upload box or drop a JPG, PNG or WEBP photo. The tool starts working immediately.
  3. Set the limits. Maximum size is 20 KB by default; type a different value if your form needs it. Enter a minimum size too if the form has one (for example 10 KB for a signature).
  4. Pick a pixel size. Use a preset such as Photo 3.5 × 4.5 cm @ 200 DPI (276 × 354 px) or Signature 140 × 60 px, choose Custom for your own numbers, or Keep original to keep the shape and only shrink if needed.
  5. Choose how to handle a different shape. Crop to fill trims the edges evenly from the centre; Fit inside keeps the whole picture and adds white bands.
  6. Check and download. The result shows the final size in KB and exact bytes, the pixel dimensions and the JPG quality used, with a before/after preview. Click Download JPG.

How the tool hits the target size

KB to bytes. The tool treats 1 KB as 1,024 bytes, so a 20 KB limit means the file must be at most 20 × 1,024 = 20,480 bytes. The result line shows the exact byte count so you can compare it with your form's rule.

Centimetres to pixels. Size in pixels = size in cm ÷ 2.54 × DPI. For a 3.5 × 4.5 cm passport-style photo at 200 DPI: 3.5 ÷ 2.54 × 200 = 275.6 ≈ 276 px wide and 4.5 ÷ 2.54 × 200 = 354.3 ≈ 354 px high. At 300 DPI the same photo is 413 × 531 px. A 4 × 2 cm signature at 200 DPI is 315 × 157 px.

Quality search. JPG file size rises with the quality setting, so the tool runs a binary search: it tries 95% quality first, then 5%, then repeatedly halves the gap (8 more steps) and keeps the highest quality whose file is still within the limit. That pins the quality down to within about 0.4%, so the file lands just under the limit without wasting quality.

Automatic downscaling. If even 5% quality is too big, the pixel size is reduced in proportion to how far over the limit it is, and the search runs again – repeated until the file fits. With Keep original, the tool also prefers a slightly smaller image over a very blurry one: if the best quality would fall below 40%, it shrinks the image by 15% and tries again, stopping when either side reaches about 320 px. Images larger than 4000 px are first scaled to 4000 px on the long side. A final check confirms the file is not over your limit before you can download it.

Worked example. In our test in Microsoft Edge, a 3000 × 2000 px, 4.1 MB JPG with the 276 × 354 px photo preset and a 20 KB limit came out at 19,344 bytes (18.9 KB) with 89% JPG quality. The same image with Keep original came out at 831 × 555 px and 20,072 bytes (19.6 KB) at 44% quality. A signature PNG with the 140 × 60 px preset needed only 2,349 bytes (2.3 KB) at the 95% quality cap. Your numbers will differ with your photo and browser, but the result is always within your limit.

Typical exam requirements

Every recruiting body sets its own rules and may change them in each notification, so always follow the official notice. As an example, IBPS notifications for bank PO and clerk exams have asked for a photograph of 200 × 230 pixels between 20 and 50 KB and a signature of 140 × 60 pixels between 10 and 20 KB. Other bodies (SSC, UPSC, NTA for NEET, state commissions) publish their own size ranges and dimensions. Use the maximum and minimum fields to match whatever range your form states.

Tips for a photo that gets accepted

  • Start with a clear, well-lit photo against a plain light background; compression works better on clean images and the result looks sharper.
  • Crop to head and shoulders first with Image Crop if the photo has a lot of empty space, so the face fills the frame.
  • For signatures, sign with a black or dark blue pen on plain white paper and photograph it in daylight. The 140 × 60 px preset keeps the file tiny.
  • If a portal still says "file too large", it may count 1 KB as 1,000 bytes. Set the maximum to 19 KB to leave a safety margin.
  • If the form has a minimum size and your output is below it, use a larger pixel preset or Keep original; a bigger image holds more data.
  • Check the pixel size of an existing file with the Image Resolution Checker.

Limitations and notes

The output is always JPG, which is what almost every exam portal requires; transparent areas in PNG files become white. Very small targets (2–5 KB) on large pixel sizes force low quality or a smaller image, and the tool tells you when it had to shrink a preset size to fit. It cannot make a blurry or dark photo meet appearance rules such as background colour or face size – those are checked by the recruiting body. Results can vary slightly between browsers because each uses its own JPG encoder, but the downloaded file is always verified against your limit.

Frequently asked questions

How do I reduce a photo to 20 KB for an exam form?

Choose your photo, keep the maximum at 20 KB, pick a pixel preset such as 276 x 354 px or the size your notification asks for, and download the JPG. The tool automatically finds the best quality that stays within 20 KB.

Will the output always be under 20 KB?

Yes. The tool checks the final file against your limit before showing it. If the image cannot fit even at the lowest quality, it reduces the pixel size until it does and tells you that it did so.

Is 20 KB counted as 20,000 or 20,480 bytes?

This tool uses 1 KB = 1,024 bytes, so 20 KB means up to 20,480 bytes. If a portal rejects a file that is just under the limit, set the maximum to 19 KB to stay below 20,000 bytes as well.

How do I resize a signature to 10-20 KB?

Choose the Signature 140 x 60 px preset (or the size in your notification), set the maximum to 20 KB and the minimum to 10 KB. If the result is below 10 KB, choose a larger pixel size such as Keep original.

What is 3.5 x 4.5 cm in pixels?

It depends on the DPI. At 200 DPI it is about 276 x 354 pixels and at 300 DPI about 413 x 531 pixels, using pixels = cm / 2.54 x DPI.

Is my photo uploaded to your server?

No. The image is processed in your browser on your own device and is never sent to MavexTech or anyone else.

Can I upload a PNG and get a JPG?

Yes. PNG, JPG and WEBP images are accepted, and the output is always a JPG because that is what most exam forms require. Transparent areas become white.

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