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CTET Signature Upload — 3 KB to 30 KB

CBSE — Central Teacher Eligibility Test requires the signature to be between 3 KB and 30 KB. A range is harder than a ceiling: compress too aggressively and the file falls under the floor and is rejected for being too small. The signature is specified as 3.5 × 1.5 cm. Accepted format: JPEG.

Compress for CTET signature

Drop an image here, or click to choose JPEG, PNG, WebP, HEIC or AVIF · processed in this browser, never uploaded
1 KB = 1024 bytes, which is how upload forms count
Set this when a portal demands a range
Government portals almost always want JPEG
Optional cap applied before compressing

The published requirement

File size 3 KB – 30 KB
Physical size 3.5 × 1.5 cm
Format JPEG

Source: CBSE — CTET Information Bulletin — read 2026-07-26.

Worth knowing

Dimensions are given as 3.5 cm long by 1.5 cm high. A 30 KB ceiling is one of the tightest here.

How to get your file to fit

  1. Drop your signature into the tool above. The target is already set to 30 KB with a 3 KB floor.
  2. Press compress. The tool searches for the highest quality that still fits, rather than picking a quality and hoping — so you keep as much detail as the limit allows.
  3. Check the reported size and dimensions against the table above before you upload. If the tool had to reduce the dimensions to reach the target, it says so.
  4. Download and upload to CTET. Keep the original file — if the portal rejects the upload for a reason other than size, you will want to start again from the full-quality image.

Other CTET uploads

CTET upload questions

How do I get my file under 30 KB without ruining it?

By searching for the right JPEG quality rather than guessing at one. The tool above encodes your image repeatedly at different quality settings and keeps the largest result that still fits — so you spend every available byte on image quality instead of overshooting and handing in something blurrier than it needed to be.

If no quality setting is small enough, it reduces the dimensions in steps and searches again, and it tells you when that happened.

My file is under 3 KB. Is that a problem?

Yes — CTET sets a floor as well as a ceiling, and an upload below 3 KB can be rejected. Set the minimum field in the tool and it will keep the file inside the window. If your image is small and flat, it may not contain enough detail to reach the floor at all; increasing the dimensions before compressing usually fixes that.

Is my file uploaded to a server?

No. Everything runs in your browser. This site is static files on a CDN with no upload endpoint at all, which is also why it is free — there is no bandwidth bill to pass on.

Can I upload a PNG or a HEIC instead?

CTET lists JPEG, so convert first. Drop a PNG or an iPhone HEIC into the tool above and choose JPEG as the output — it will be decoded and re-encoded in one step. PNG is also a poor fit for a KB target: its quality setting does nothing, so the only way to shrink a PNG is to make it smaller in pixels.

Why does the size shown differ slightly from what the portal reports?

Because "KB" is ambiguous. This tool uses 1 KB = 1024 bytes, which is what upload validators almost always use. Some file managers use 1 KB = 1000 bytes, which makes the same file look about 2.4% larger. If you are right on the edge of a limit, aim a few KB under it.

Is this the current requirement?

It was read from CBSE — CTET Information Bulletin on 2026-07-26. Dimensions are given as 3.5 cm long by 1.5 cm high. A 30 KB ceiling is one of the tightest here. Exam and recruitment bodies change these figures between cycles, so check the notification or bulletin for the exam you are actually applying to.

Other India portals

Check your own notification. img-fix is not affiliated with CTET. This figure was read from CBSE — CTET Information Bulletin on 2026-07-26. Exam and recruitment bodies change upload rules between cycles, so the bulletin for the exam you are actually sitting is the authority.