Compatibility and honest limits.
Use current Chrome, Edge, Firefox or Safari with JavaScript enabled. Desktop browsers are recommended for large PDFs, OCR and complex editing. Browser-local does not mean unlimited or completely offline.
| Workflow | Supported | Limit or trade-off |
|---|---|---|
| Compare PDF | Selectable text and visual overlays | Up to 50 MB / 200 pages per file; no automatic OCR or visual-equality certification |
| Text editing | Supported original-font page text runs | No paragraph reflow, scans, XObjects or unavailable font glyphs |
| PDF/A | Image-based PDF/A-2b | Up to 50 pages; no searchable text or interactive features; independently validate each output |
| Flatten | Standard AcroForm field appearances | Not every annotation; signed PDFs and XFA rejected |
| Form creation | Text, checkbox and dropdown | Upright pages; printable English defaults; no signature certificates or scripts |
| PDF to Text | Selectable text, page ranges, UTF-8 | Not OCR; check columns and reading order |
| DOCX / XLSX / PPTX | Text-first Word, row-based tables, page-image slides | Not a guarantee of original Office layout or editable slide objects |
| Repair / validation | Readable structure and normalization | Not malware scanning, signature validation or full archival conformance checking |
Images and text tools
JPG, PNG and WebP are the main image formats. HEIC depends on a separately loaded decoder and SVG rasterization depends on supported browser rendering. Use the limit shown in each workspace: around 25 MB / 40 megapixels per image and 50 MB / 200 pages per PDF are recommendations, not guarantees of success. Background removal is a simple connected-background workflow, not general AI subject segmentation.
What has been verified
Automated synthetic regression checks cover actual text-stream replacement, preservation of neighboring text, original-font glyph rejection, form-field creation, reopening saved values, widget removal after flattening, text comparison, and archival metadata. An image-based archival fixture passed the independent veraPDF PDF/A-2b profile. These checks do not certify every uploaded file or replace device testing.
Browser and device support
Desktop Chromium release QA exercises synthetic-file workflows and output checks, as described in our testing approach. Native file-picker integration and other browser/device combinations are intended targets, not a claim of completed real-device certification. Test a small non-sensitive sample in the browser you plan to use. Mobile browsers can run out of memory sooner, especially during OCR or multi-page rendering.
Privacy and network use
Your selected files stay in the browser during supported processing. Helper code and OCR language data are served from this website. Optional analytics requires permission. Downloads and comparison reports can contain sensitive information. Read the privacy policy and your organization’s requirements.
Troubleshooting guide · Report a compatibility issue
Try a known sample first
Use synthetic files with expected page counts, text and form values. Compare the actual downloaded result, not just the preview.
Worked examples and sample files · Testing approach and limitations