About PhotoToKB
Six small tools for one problem: making a photo match exactly what an upload form demands — a KB limit, pixel dimensions, a particular format — without sending it to anyone.
Why it exists
Exam boards, scholarship portals, passport applications, visa centres and job sites all set hard limits on the files you upload — “must be less than 50 KB”, “between 20 KB and 100 KB”, “200 × 230 pixels”, “JPG only”. Miss one of those by three kilobytes or ten pixels and the form rejects you, usually without saying which rule you broke.
Most image tools answer a different question. They ask you to pick a quality percentage, or drag a slider, and find out afterwards what size you got: export, check, guess again. PhotoToKB works the other way round. You give it the requirement — the KB cap, the exact pixels, the format, or the name of the document — and it finds the best-looking file that satisfies it.
There is no upload, no queue, no account and no watermark, and none of that is a promise about a server being trustworthy: the work happens inside the page you are reading, so there is no server involved to trust.
What the toolkit does
Six jobs, four pages, all of them free and all of them local to your device:
- Compress image to exact KB — Hold a photo under 20, 50, 100 or 200 KB — or any figure you type — at the best quality that fits.
- Bulk compress photos — Up to thirty images to the same KB limit in one pass, back as a single zip file.
- Resize image to exact pixels — Name a width and height — 600×600, 200×230, 413×531 — and keep or ignore the aspect ratio.
- Crop and rotate a photo — Trim to a square or the ratio a form expects, and straighten a sideways phone photo.
- Convert HEIC, WebP & more to JPG — HEIC, TIFF, WebP, AVIF and BMP in — JPG, PNG or WebP out, ready to upload or compress.
- Passport photo & signature size — The exact pixels and KB cap a named form wants, chosen for you — India, Nepal, the US, the UK.
Two more layers sit on top of those. The converter has a page for each common pair — HEIC to JPG, WebP to JPG, PNG to JPG and six others — and the passport tool has one per document, so an India passport photo, a US visa photo or an SSC signature arrives with its pixels, format and KB cap already filled in.
How it works in your browser
Every tool follows the same three steps. Your file is decoded by the browser's own image stack, redrawn onto a canvas at whatever size the job needs, and re-encoded as JPG, PNG or WebP. Nothing in that chain involves a network request, which is why the page keeps working if you go offline after it has loaded.
The part worth explaining is how a KB target is hit. The tool searches for the highest JPEG quality that still lands under your limit, and only reduces the pixel dimensions when quality alone cannot get there. That order matters: a slightly smaller photo at good quality stays readable, while a full-size photo pushed to the lowest quality goes blotchy. When a form fixes the pixels as well as the KB — most passport and signature specs do — the dimensions are held exactly and only quality moves.
Two useful side effects. Re-encoding discards EXIF metadata, so the file you download carries no camera model, timestamp or GPS location. And a bulk run is zipped in the page itself, so thirty compressed photos come back as one download without any of them having left your device. See how it works for the same explanation step by step.
What it deliberately does not do
An honest list is more useful than a feature list. This tool will not:
- Invent detail. There is no AI upscaling and no sharpening pass. Pixels that were thrown away to meet a limit are gone; keep your original.
- Remove or replace a background. If a form wants a plain white background, the photo has to be taken against one. Transparent PNGs are flattened onto white when the output is a JPG, because JPG has no transparency.
- Keep an animation. An animated GIF, APNG or WebP comes out as a single still frame, and the tool says so before you download it.
- Decode a format your browser cannot. HEIC from an iPhone, TIFF scans and JPEG XL all open in Safari on iPhone and Mac, which uses the system image stack; Chrome and Firefox cannot read them, and you get a message naming the format instead of a silent failure.
- Guess a requirement for you. The presets carry the numbers each issuing authority publishes, but the instructions on the form you are filling in are the ones that count. Check them.
If something on that list is blocking a submission, email me — real form wording is what the next preset gets built from.
Who makes it
PhotoToKB is a small independent project built and maintained by one developer. There is no company behind it, no investors, and nothing to sign up for. It stays free because a site that does all its work in your browser costs almost nothing to host.
See the privacy policy for exactly what is and is not stored, and the terms for the legal side.