Type the KB figure your form demands into the open size field, or tap a preset chip, then drop the photo. It comes back at or under that number, never over. Part of the image compressor.
Output format
– / –
Drop images or browse
JPEG · PNG · WEBP · AVIF · HEIC · up to 50 at once · max 30 MB each
HEIC
PNG
JPEG
AVIF
WEBP
Advanced settings1 on
SmallerAutoBetter
Auto tunes each image.
A hard cap for the number your form demands.
KB
A floor for forms that refuse small files.
Max resolution
×
Empty side keeps the ratio. Never enlarges.
Every size target, one guarantee
A page for each number, arriving with the cap already armed. Under it, or a clear error, and never over.
The engine behind the cap, on a real photograph: 9.8 MB in, 97.1 KB out. Your file gets the same treatment with your size limit as the hard ceiling.
How do I reduce image size in KB to a number I choose, never over?
Type the number into the Max file size field, already open under the drop zone, and drop the photo. The field counts in KB, one KB being 1,000 bytes. The chips beside it arm 50 KB, 100 KB, 200 KB or 1 MB with one tap. The engine then binary-searches quality for the most detail that fits at or under your number. If no quality fits, it shrinks the dimensions, down to a 64-pixel floor, before it gives up. The output is at or under the cap, never over, and the readout under each result prints the exact size. JPEG output is preselected because JPG is the format the portals in the next table name.
Which KB caps do portals actually use?
Tens to hundreds of kilobytes, and almost always as a window with a floor. Each rule below is quoted from the notice or help page named in its row, as it read when we checked it.
Cap
Who states it
The rule, in its words
30 KB
Kerala PSC photo instruction
Profile photo 150×200 px and signature 150×100 px, JPG, each not exceeding 30 KB
100 KB
GST registration guide (India)
Photograph of the promoter or authorised signatory, JPEG, at most 100 KB
150 KB
Google Ads help; AAMC ERAS photo page
An uploaded image ad at most 150 KB in GIF, JPG or PNG; the ERAS residency photo at most 150 KB as JPG or PNG
Passport-size photograph 10 KB to 200 KB, JPG; UPSC photograph 20 KB to 200 KB and signature 20 KB to 100 KB, .jpg
300 KB
NTA, NEET (UG) 2026 bulletin; Naukri CV upload
Scanned certificates as PDF, 50 KB to 300 KB; a CV as Word or PDF at most 300 KB
The Kerala PSC figures come from the commission's photo instruction, the NTA figures from its NEET (UG) 2026 information bulletin, the UPSC figures from its 2026 examination notices, the GST figures from its registration user guide, the Google Ads figure from its help page, the ERAS figure from the AAMC's photo page, and the Naukri figure from its CV upload page. Check the current notice before you upload; the source is the authority.
Why is the cap a window, and which lever do I pull first?
Because a portal states a floor as well as a ceiling, and often a pixel rule beside them. Bytes pay for pixels, so the order matters: pixels first, then the cap.
1
Read the whole rule
The NTA's NEET notice states a floor and a ceiling for every image on the form, with a smaller window for the signature. UPSC's notices do the same. The number you type is the top of the window. The readout under your result tells you that you sit above the floor.
2
Set the pixels if the portal states them
Type the portal's width and height into Max resolution in the same panel, or crop to the exact size first. A big picture under a small cap spends its whole budget holding pixels together; a right-sized one spends it on the face.
3
Then type the cap and drop
Our 576.8 KB reference photo, 1920×1280, kept every pixel under a 50 KB cap, at 48.7 KB. Our 9.8 MB camera photo, 4964×2782, had to shrink to 1371×768 to fit the same cap. Same number, opposite outcomes, and the pixels decided it.
Is 1 KB 1,000 bytes or 1,024 bytes, and does it matter for the upload?
Both are in use, and the field here counts 1,000. NIST's page on binary prefixes defines the prefix kilo as 1,000 and the binary prefix kibi as 1,024. Of the two it says "the confusion is real". Apple's support note on storage says current Apple systems report sizes in decimal, while iOS 10 and OS X Leopard and earlier used binary. So one file can read as a different number of KB on two screens. That is the trap behind "my 100 KB file was rejected". A file of 101,500 bytes shows as 99 KB on a screen that counts 1,024, and fails a portal that counts 100,000. Typing 100 KB here caps the file at 100,000 bytes, which is under 100 KB by either count.
Will reducing to KB ruin the photo? Measured at 20, 50, 100 and 200 KB
Not from 50 KB up. Our 576.8 KB reference photo, 1920×1280, kept every pixel at 50 KB, 100 KB and 200 KB; the bytes came out of the quality setting alone. At 20 KB no quality level fit the full frame, so the engine brought it down to 576×384.
Cap
Result
Dimensions
What the engine did
20 KB
18.3 KB
576×384
quality search, then a downscale
50 KB
48.7 KB
1920×1280
quality search alone
100 KB
99.7 KB
1920×1280
quality search alone
200 KB
199.2 KB
1920×1280
quality search alone
Source: photo.jpg, 576.8 KB at 1920×1280, through Max file size at each cap with the engine's defaults. Each row is the file the engine produced.
Every byte count is the size of the actual file our engine produced from the named source, the same bytes you would download, not an estimate. The reference photo is one of our own photographs, an iguana on a branch, and the camera photo is a real one too. Drop your own file into the tool above to rerun any of them. How we measure names the sources and the settings.
Photo resizer in KB, KB resizer, resize image in KB: the same tool as this one
The forms say it a dozen ways and mean one thing: a file whose size in kilobytes is a number they set. Photo resizer in KB, KB resizer, resize image in KB, image KB reducer, size reducer in KB, KB converter, photo size in KB, image to KB: all of them are this page, with the size field already open in KB.
JPG resize in KB: the bytes move, not the pixels
A resizer that promises a KB figure is hitting a byte target, and may drop pixels to get there. Changing only the pixel dimensions is a different job, and the image resizer does that: width and height in, bytes follow.
How do I reduce photo size in KB on a phone without installing an app?
Open this page in the phone's browser; there is nothing to install. The tool takes iPhone HEIC as it comes off the camera and returns a JPEG, the format the portals above accept. Android JPEGs go straight through. The Advanced panel is open on arrival with the size field and its chips. The download lands in the phone's files like any other. The job an app store calls a "photo size reducer" is this page, with no install.
Can I reduce the KB size of fifty images at once, to one cap?
Yes: 50 files per batch, one cap applied to every one, one ZIP back with the filenames kept. A measured size prints on every row. A folder of application photos is one drag. When the form wants two caps, say a 200 KB photo and a 30 KB signature, run two batches. The cap is per batch, not per file. The free allowance is 300 images a day, counted live beside the tool, with no account.
Is it safe to upload ID photos and signatures here?
Yes. The defaults were set for exactly these files. EXIF and GPS come off every output, files are processed and wiped automatically, and no account collects your uploads. A signature scanned at the kitchen table leaves without the kitchen table in it. The privacy policy carries the detail.
When KB is the wrong unit
The field says 1 MB or 2 MB?
Switch the unit selector to MB, or use the megabyte page, which is built for the caps that keep every pixel.
The form wants pixels, not bytes?
Set Max resolution in the same panel, or use the resize tool for an exact width and height.
A cap under 10 KB?
The size field starts at 10 KB. Crop tight and shrink the dimensions first; the smallest caps then fit.
A PDF, not a picture?
Cap the page images here, then let the image-to-PDF converter assemble them; its wrapper adds a few kilobytes on top.
The panel is already open above. One drop settles most of these.
Q:What does it mean to reduce image size in KB?
It means bringing the file under a stated number of kilobytes without changing what the picture shows. A form that says "under 100 KB" is counting bytes, not pixels. A compressor gets there by re-encoding the photo at a lower JPEG quality, and shrinks the dimensions only when quality alone cannot reach the number. The picture stays the same size on screen; the file gets lighter.
Q:How do I reduce photo size in KB?
Type the kilobyte figure into the Max file size field, or tap one of the chips, then drop the photo. The engine searches for the highest quality that fits at or under that number and hands back a JPEG with its exact size printed beside it. Nothing to install and no account. Up to 50 photos take the same cap in one batch.
Q:How do I reduce JPG or JPEG size in KB?
Drop the JPG with a cap typed into the size field. JPEG is the friendliest case: the engine re-encodes it at the highest quality that fits under your number and keeps the dimensions whenever it can. Our 576.8 KB reference photo reached 99.7 KB under a 100 KB cap and 48.7 KB under 50 KB, both at its full 1920×1280.
Q:How do I reduce PNG size in KB?
Two routes. For a photo saved as PNG, keep the preselected JPEG output: photographic pixels compress far smaller as JPEG, and portals expect JPEG anyway. For a graphic, signature or screenshot that must stay PNG, pick PNG in the format picker. Under a cap the engine trims the palette, down through 256, 16, 4 and 2 colours, until the file fits.
Q:Is this an image to KB converter?
In effect, yes, though nothing is converted: the picture stays a picture and the bytes come down to the kilobyte figure you type. The phrase usually means a tool that takes a file measured in megabytes and returns one measured in kilobytes. The tool does that with a hard ceiling instead of a slider, and prints the resulting size so you can check it against the form.
Q:Is this an image KB reducer, or a photo size reducer in KB?
Both, since the two names mean the same job: a smaller file, measured in kilobytes. The distinction worth making is bytes against pixels. The tool reduces bytes to the number you type and leaves the dimensions alone unless the cap forces a downscale. To reduce pixels, the width and height, use the resize tool or set Max resolution in the same panel.
Q:How do I compress the image size in KB for a government portal?
Read the portal's rule as a window, not a single number. The NTA's NEET notice wants the passport-size photo between 10 KB and 200 KB in JPG. UPSC's 2026 exam notices want the photo between 20 KB and 200 KB. Type the top of the window as your cap, keep JPEG as the output, and check that the readout sits above the floor.
Q:Is a KB photo size the same as the pixel size?
No. The KB photo size is the file's weight on disk; the pixel size is its width and height. A portal can rule on both, and a file can pass one and fail the other. Kerala PSC's instruction, for one, wants a 150×200 px photo that does not exceed 30 KB. Crop to the pixels first, then let the cap hold the bytes.
Q:How do I decrease the KB size of an image without losing pixels?
Type the cap. The engine lowers quality first and resizes only when nothing fits. Our 576.8 KB reference photo, 1920×1280, kept every pixel at 50 KB, 100 KB and 200 KB; the bytes came out of the quality setting alone. At 20 KB no quality level fit the full frame, so the engine brought it down to 576×384.
Q:How do I compress an image to 100 KB or 200 KB?
Tap the 100 KB or 200 KB chip beside the size field and drop the file. The cap is armed and the result lands at or under it. Each of those numbers also has a page of its own with the cap armed on arrival, as does every cap in the chip row. Bookmark the one your portal names.
Q:How do I reduce image size in KB on my phone?
Open the tool in the phone's browser, type the number and pick the photo from the camera roll. iPhone HEIC files are accepted as they are and come back as JPEG. There is no app to install and no account to create. The compressed file saves to the phone's downloads, ready for the portal's upload button.
Q:Is 1 KB 1000 bytes or 1024 bytes?
NIST's page on binary prefixes defines kilo as 1,000 and the binary prefix kibi as 1,024, and both counts are in use. Apple's storage note says current Apple systems count in decimal while older ones counted in binary. The size field here counts 1,000 bytes per KB, so a 100 KB cap means 100,000 bytes. That is under the limit whichever way the portal counts.
