PostScript to WebP Converter

PostScript to WebP: Start With the PDF Step

.ps is a PostScript file — a program in Adobe's page-description language that paints a page when a PostScript interpreter runs it. WebP is the opposite kind of thing: one finished raster image, built for the web, roughly a quarter smaller than the JPEG or PNG equivalent. Getting from one to the other means rasterizing the page, and on this site that rasterizer is a PDF renderer, so the PostScript has to become a PDF first. A genuine .ps uploaded here does not come back as a WebP: the renderer looks for PDF structure (%PDF- and a cross-reference trailer), a PostScript stream (%!PS-Adobe-…) has neither, and the job ends in an error. Make the PDF yourself — one Ghostscript command — and PDF to WebP finishes the job with the exact controls described below.

How to Convert PostScript to WebP

1. Convert the .ps to PDF on Your Own Computer: ps2pdf input.ps output.pdf does it in one line. ps2pdf wraps Ghostscript's pdfwrite device, which is free for Windows, macOS and Linux; any "Print to PDF" or "Save as PDF" route from an application that can print the file works just as well.
2. Upload the PDF to the WebP Converter: Open PDF to WebP and drop the PDF in, or click "Add Files". Every page becomes its own WebP image.
3. Set Conversion Quality, Then Decide Lossless: Conversion Quality is the render DPI — 72, 96, 150, 200, 300 (preselected), 400, 600 or 1200 — and it fixes the pixel dimensions. "Lossless?" opens on No (Recommended) with the Quality Preset at Very High; switch it to Yes for a bit-exact page. Image Transparency picks the colour behind the page (White unless you change it), and Image resolution can shrink the finished raster.
4. Convert and Download: Click Convert and save the WebP, or grab the ZIP for a multi-page document. No sign-up and no watermark; files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours.

Lossy or Lossless: What the Toggle Actually Changes

WebP is two codecs wearing one extension, and the toggle chooses between them. That choice matters more than the DPI for a page full of text, because lossy WebP is a VP8-derived transform that puts ringing around sharp black-on-white edges, while lossless WebP is an entropy coder that reproduces them exactly.

The size figures come from Google's own WebP comparison, measured against PNG and JPEG at matched quality.

Sizing the Render

• The DPI is the resolution. A page description carries no pixels of its own, so Conversion Quality decides them: 300 DPI makes an A4 page 2480 × 3508 px, 150 DPI makes it 1240 × 1754 px, and 600 DPI makes it 4961 × 7016 px. Nothing recovers detail after the fact.
• Render high, then scale down. Image resolution rescales the finished raster — a 600 DPI render dropped to a 1080p height keeps sharper glyph edges than a 96 DPI render at the same final size.
• The page is always flattened onto a colour. WebP supports an alpha channel in both modes, but the "Unchanged" transparency option is offered only for PNG output, so this route composites the page onto the Image Transparency colour — White unless you choose one of the other 24. If you need a real alpha channel, use PDF to PNG instead.
• Everything current can display the result. All versions of Chrome, Edge, Firefox and Opera decode WebP; on Apple hardware it needs Safari 14 or later and macOS 11 or later, per MDN's image format guide.

Why the PostScript Step Is Manual

PostScript is Turing-complete. A .ps file does not describe a page so much as compute one, which is why rendering it needs a full interpreter — Ghostscript — rather than a parser. PDF took the same imaging model and threw away the programming language, leaving a static object graph that a parser can walk. Our page pipeline is built on the parser, so it reads PDF and not PostScript.

Two practical consequences follow. First, a real PostScript upload fails outright rather than producing a partial image, so changing the DPI or the Lossless toggle and retrying will not help. Second, if a file named .ps does convert here, it was PDF data all along — renderers identify files by their header bytes, not their extension, so a renamed PDF passes straight through. That is a useful test in itself: open the file in a PDF viewer, and if it opens, you already have the PDF and can skip step 1.

WebP Against the Other Page-Image Targets

Frequently Asked Questions

Why did my PostScript file fail instead of converting to WebP?

Because a PDF parser cannot read a PostScript program. The renderer expects the %PDF- header and a valid cross-reference trailer; .ps files begin %!PS-Adobe- and have neither, so the parse throws and the job reports an error with nothing partial written. Run ps2pdf input.ps output.pdf first, then upload the PDF to PDF to WebP — same renderer, same options, working result.

Should I pick lossy or lossless for a page of text?

Lossless, in most cases. A rendered page is flat colour and hard edges, which is exactly what the lossless coder handles well and what lossy VP8 blurs — you will see haloing around small type at the lower presets. Lossy is the better choice when the page is mostly photographic, where it earns its 25–34% saving over JPEG without a visible cost.

Does the Quality Preset do anything in lossless mode?

Not to the image. In lossless mode the preset acts as a compression-effort dial: we encoded the same rendered page across the range and every output was pixel-identical, with only a few percent difference in file size between the extremes. In lossy mode the same preset is a genuine fidelity control, which is why the two modes need different habits.

Can the WebP keep transparency from the page?

Not on this route. WebP itself supports alpha in both lossy and lossless modes — Google puts the cost at about 22% extra bytes for lossless — but the option to preserve page transparency is exposed only for PNG output here, so the page is composited onto the Image Transparency colour. Choose PDF to PNG when you need the alpha channel to survive.

What DPI should I choose for a web image?

For an image that will be displayed at page-thumbnail size, 96 or 150 DPI is plenty and keeps the file small. For a preview a reader might zoom into, render at 300 DPI and then use Image resolution to bring it down to the display size — downscaling a high-resolution render preserves glyph shapes far better than rendering coarse in the first place. Reserve 600 and 1200 DPI for fine line art.

What happens to a multi-page PostScript document?

Each page becomes its own WebP. A four-page document gives four numbered files, downloadable individually or as a ZIP; there is no single WebP that holds a stack of pages, because WebP is a single-image format. The PDF you made in step 1 is already the multi-page container if you need one.

Will the text still be selectable in the WebP?

No. Rasterizing writes pixels and discards the text objects, so nothing in the output can be selected, searched or edited — the same is true of every image format on this list. Keep the intermediate PDF alongside the image if the text needs to stay live.

How are my files handled, and how long are they kept?

Uploads travel over an encrypted connection and are rendered on our servers; this is not an offline tool. Uploads and outputs are deleted automatically after a few hours, are never shared or made public, and no account is needed. There is no watermark on anything we produce and no sign-up between you and the download.