100KB SDK

100KB SDK is a client-side WebAssembly toolkit for adding image and document processing to a web product. It handles the work in the user's browser before a file reaches application storage, which can reduce the amount of data sent to services such as Amazon S3 or Cloudflare R2. The package is aimed at developers who need more than a basic image compressor. Its documented methods cover images, PDFs, signatures, passport photos, background removal, format conversion, and other upload preparation jobs. A companion Web Component offers a lower-code path for sites that don't want to build the full interface around the npm package.

The central idea is local processing. A file stays in browser memory while WebAssembly performs compression or conversion, then the application can upload the resulting blob through its existing pipeline. That design is useful when an app handles identity documents, application forms, medical files, or customer photos and would rather not send the original file to a separate compression service. It also removes a remote compression request from the critical path. The official documentation shows a standard npm installation and direct functions such as compressImage and compressPDF, along with an initialization step. An API key is optional for the free branded mode and is used to unlock an unbranded commercial license.

The image tools go well beyond a single quality slider. Developers can set a target size in kilobytes, choose JPEG, PNG, or WebP output, cap dimensions, and use presets for common portals. Additional methods convert HEIC photos to JPEG, switch between PNG and JPEG, resize or crop images, adjust a file toward a minimum size, and run batch work through Web Workers. There are specialized flows for sharpening and compressing signatures, combining a photo with a signature, removing backgrounds, cleaning stamp or date artifacts, and creating passport photos with country presets. The PDF side can compress toward a size ceiling while preserving vector text, merge files, split selected pages, create PDFs from images, export pages as JPEGs, convert content to an editable Word file, and remove supported document restrictions.

100KB SDK fits product teams whose upload requirements are unusually strict. A recruitment portal may need signatures below 20KB. A visa service may need an image cropped to a defined head ratio and kept under a submission limit. An e-commerce store may want to shrink customer artwork before it enters cloud storage. A SaaS product may simply want one browser-side package for several media tasks instead of assembling and maintaining multiple libraries. The official integration hub provides examples for React and Next.js, Vue, Angular, Svelte, Node.js, Python, PHP, and plain Web Components. WordPress and Shopify also have dedicated integration material, so the product isn't limited to teams building a custom JavaScript frontend from scratch.

Its clearest differentiator is the combination of target-size processing and local execution. Many browser image libraries can resize a picture, but this SDK is organized around exact file-size ceilings and document workflows that appear in application forms and regulated submissions. The same package also groups image and PDF operations with more specialized jobs such as passport framing and signature preparation. That breadth can reduce integration work when a product needs several of those functions together. Still, teams should test output quality and browser performance with their own files. A target size is a constraint, and aggressive compression can involve visible tradeoffs. The broad API also means adopters need to choose carefully which capabilities belong in their user experience.

Privacy is another practical reason to consider it. Because the raw input is processed locally, an application doesn't need to forward that original file to 100KB for the documented browser workflows. This can simplify the data flow and reduce exposure to another processing server, although it doesn't replace a product's own privacy, security, or compliance work. Once processing finishes, the host application still decides where the result goes and how it is protected. Local execution also shifts compute to the user's device, so teams serving older phones or processing large batches should evaluate responsiveness under realistic conditions. The SDK includes a parallel Web Worker batch method, but device resources remain part of the experience.

Access follows a freemium licensing model. The Developer Free tier is listed at $0 forever with unlimited local operations, no API key, all documented media and document APIs, and a visible Powered by 100KB link. The Commercial License costs $19 per month or $149 per year and removes that branding. It also adds an automated domain lock, a commercial license key, and the higher precision passport cropper described in the plan comparison. Both tiers keep execution local, and the pricing page says there are no monthly operation limits. That makes the free tier useful for evaluation and community or open-source work, while production SaaS products, stores, and agencies can pay for an unbranded deployment. Enterprise inquiries and custom WebAssembly builds are available separately, but the public pages don't publish a fixed enterprise price.