Tinkr
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Student·Live· Compressed in your browser

Compress PDF

Shrink a PDF by rasterizing each page at a lower DPI and JPEG quality. Trade pixel sharpness for file size — pick the smallest setting that still looks acceptable. Runs entirely in your browser.

Drop a PDF here, or click to browse
Pages are rendered locally; nothing uploads.
Compressed entirely in your browser

Pages are rendered to canvas via pdf.js, JPEG-encoded, and rebuilt into a fresh PDF with pdf-lib — all in your browser tab. Nothing uploads. Safe for tax forms, medical records, and confidential briefs.

Frequently asked questions

Is my PDF uploaded to compress it?
No. Each page is rendered to canvas and re-encoded as JPEG entirely in your browser, then rebuilt into a fresh PDF with pdf-lib. The original file never leaves your machine. You can use the tool offline once the page has loaded.
How does the compression actually work?
We render each PDF page to a canvas at a chosen DPI (lower = smaller), then JPEG-encode the canvas at a chosen quality (lower = smaller). The resulting JPEGs are embedded into a new PDF at the original page dimensions. This is a lossy approach — vector text becomes raster — but it's effective on scan-heavy PDFs.
When will compression NOT save much?
Pure-text PDFs (e.g., a Word export of a research paper) are already very efficient — vector text takes only a few bytes per glyph. Rasterizing them at a low DPI can actually increase the file size or make text fuzzy. For text-heavy PDFs, expect modest savings or use the original.
What DPI should I pick?
72 DPI is screen-only — readable on a monitor but pixely if printed. 96 DPI (the default) is a good balance for most documents. 150 DPI matches typical print quality. 200 DPI keeps near-original sharpness while still shaving size on photo-heavy PDFs.
What about JPEG quality?
0.5 is aggressive — visible artifacts on photos and gradients but maximum savings. 0.7 (default) is the standard 'good enough' setting most JPEG encoders use. 0.85 is near-lossless and only saves marginally on already-compressed scans. Pick the lowest setting where the result still looks acceptable.
Does it work for password-protected PDFs?
No, not yet. Encrypted PDFs need to be decrypted first. Open the PDF in a viewer that knows the password, save a copy without encryption (Print → Save as PDF), then run that copy through the compressor.
What's the maximum file size?
Around 50–100 MB depending on your browser and machine. The whole PDF is rendered to canvas one page at a time, which can be memory-hungry. If your PDF is very large, split it first (use the Split PDF tool), compress each piece, and merge them back.
Will text still be searchable after compression?
No. Because each page is converted to a JPEG image, the text is no longer present as selectable/copyable text. It's only pixel data inside an image. If you need searchability, run OCR on the compressed PDF afterward, or stick with the original.

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