PDF tools
Merge, extract, edit, and convert PDFs without uploading documents.
INTERNAL PRODUCT / ASYNC UTILITIES
We built 16 browser tools around one rule: keep the file on the user's device.
Async Utilities is our own product, not a client engagement. We designed and engineered the collection to show how a small web application can handle real document and image work without an account or an upload to Async.
Use the tools- Working tools
- 16
- Workspaces
- 4
- Accounts required
- 0
THE BRIEF
Make common file tasks quick without asking users to hand over their files.
Online utilities often put a server between the user and the result. That creates a privacy question before the work even starts. We chose browser APIs and client-side libraries so PDFs, images, and document data could stay on the device during processing.
The product still needed clear limits, useful errors, and downloads people could trust. We treated those constraints as interface decisions rather than details to hide in fine print.
PRODUCT SCOPE
Four focused workspaces, each built for a specific job.
Document generators
Create polished invoices, payslips, resumes, and certificates.
Design tools
Explore colors, gradients, icons, and typography with live previews.
Image tools
Resize, compress, convert, and remove backgrounds in your browser.
BROWSER-FIRST ARCHITECTURE
The interface, processing, and download all run in one browser session.
01Select
The browser reads the chosen file or form data.
02Process
Client-side code creates the requested output on the device.
03Verify
The tool checks limits, state, and the result before enabling a download.
04Download
The browser saves the finished file without sending the source to Async.
ENGINEERING DECISIONS
The edge cases shaped the product.
Set limits before the browser runs out of memory.
PDF conversion accepts files up to 50 MB and 200 pages. The merger supports up to 30 files and 200 MB combined. Image tools cap inputs at 20 MB and 40 megapixels, while resizing stops at 12,000 pixels per side.
Keep optional network requests visible.
The background remover downloads a roughly 30 MB browser model on first use. The Font Pairer loads Google Fonts only after the user enables external previews. Source files still remain on the device.
Invalidate stale output.
If a source file, format, order, or quality setting changes, the previous result can no longer be downloaded. Image conversions also check the returned MIME type so a browser cannot produce a mislabeled file.
Make recovery part of the interface.
Encrypted or damaged documents return a clear error. Range inputs explain what failed. PDF edits can be applied in sequence, while Reset restores the untouched original.
WHAT THIS WORK SHOWS
Product thinking backed by shipped software.
A coherent system, not a pile of demos.
Shared navigation, content patterns, error behavior, and visual language make sixteen tools feel like one product.
Complex work can stay client-side.
PDF parsing, canvas rendering, document generation, and browser AI run behind interfaces that explain their limits.
The work is live and available to test.
Every claim on this page maps to a working tool. You can inspect the behavior, try the edge cases, and judge the result yourself.
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BUILD SOMETHING USEFUL
Need a product or internal tool with this level of care?
Tell us who will use it, what the current workflow gets wrong, and what a successful first release needs to do.
Discuss your project