Free PDF Contract Editors Compared: Highlight, Comment, Redact, Sign

"Free PDF editor" is not one product decision, it is five. You might need to highlight a clause and drop a comment for your manager, actually change a sentence in a draft, permanently black out a bank account number, fill in and sign a form, or merge annexures into one file. Almost no free tool does all five well, and none is Adobe's paid Acrobat Pro. We tested eight side by side against a real vendor contract, including Weave, the free browser tool Adira (which publishes this Journal and sells contract review and CLM software) built for reading and marking up contracts clause by clause. That makes this comparison not fully neutral, but every number below is checkable in a few minutes, and we say plainly where Weave is not the right tool either.

The five jobs hiding inside "PDF editor"

People say "I need to edit this PDF" and mean one of five different things, and the tool that is best at one is often weak or missing on the others.

1. Highlight and comment. Marking a passage and leaving a note; this does not change the contract, it is a flag for discussion.
2. Edit text. Changing the actual words on the page, not adding a note over them.
3. True redaction. Permanently removing sensitive text, not covering it with a shape.
4. Fill and sign. Completing form fields and adding a signature.
5. Merge and split. Combining or separating pages, for stitching annexures on or pulling one schedule out.

A tool can be excellent at the first job and useless at the third. Xodo and PDF24 are strong on highlight and merge, weak or paywalled on redaction. LibreOffice Draw is free at everything and reliable at almost nothing. Knowing which of the five you need before you pick a tool saves you downloading three apps to do one job.

The comparison, tested against a real contract

Tool	Highlight/comment	Edit text	True redaction	Fill & sign	Merge/split	Free limit	Watermark	Signup/card	Data
Browser-native	Yes	No, view-only layer	No tool	Fill yes; drawn/typed signature	No merge tool	None, fully free	None	None	Local
Xodo	Yes, free	Overlay text boxes only	Partial: 1 free redaction/day on web tool, then paywalled	Yes, free	Yes, free	1 redaction/day on web; app unrestricted	None found	None	App local; web redact/merge tools upload
PDFgear	Yes, free	Desktop: real edits. Web: text boxes only	Yes, marketed as permanent (verify below)	Yes, free	Yes, free	None stated on desktop	None	None	Desktop local; web tools upload
Sejda	Yes, free	Yes, real in-place edits	Yes, marked "permanent" (verify)	Yes, free	Yes, free	3 tasks/hour, 200 pages, 50MB/file	None within limits	None	Web-only; every file uploads
LibreOffice Draw	Weak: pages are flat images, "highlight" is a drawn box	Weak: usually breaks layout	No tool; a black box is not redaction	Weak: signature is a placed image	Yes, via export, free	None, free forever	None	None	100% local
PDF24	Yes, free	Overlay text boxes only	No dedicated tool	Yes, free	Yes, free	No task cap; web upload ~15MB/file	None	None	Desktop local; web tools upload, auto-deleted
Foxit Reader (free)	Yes, free	No, paid Editor only	No, paid Editor only	Yes, free (image/e-sign)	No, paid Editor only	None on free features	None	None	Local
Weave (Adira, free)	Yes	Not built for this	Not built for this	Not built for this	Not built for this	None, fully free	None	None	In-browser, never uploaded

What we actually found testing each one

Sejda's limits are precise rather than vague: 3 tasks an hour, a 200-page cap, 50MB per file, then you wait an hour or pay. For one contract that rarely bites; for a bulk job across a folder of agreements, you will hit the wall fast. Its text editing is genuinely in-place, not an overlay box, unusual for a free web tool.

PDFgear splits in two. The desktop app does real text editing, replacing the actual characters, the way Acrobat Pro does; the web version at pdfgear.com only drops a text box on top, which looks similar but is not the same file underneath. Check which version a marketing screenshot is showing before assuming the free web tool can do the same.

Xodo is the strongest all-rounder for highlight, comment, and merge/split, genuinely free with no daily cap on the reader app. Its redaction tool is real, actually removing the text, but lives mainly on Xodo's website, so the file uploads, and it is capped at one free permanent redaction a day.

LibreOffice Draw is worth reaching for only when nothing else is available. It treats each PDF page as a flat image, so a "highlight" is a rectangle on top of a picture, and editing text usually shifts the layout around it. Completely free and fully offline, its one real advantage.

PDF24 is close to Xodo for breadth (highlight, edit via text box, merge, split, convert), no daily task cap, but no dedicated redaction tool, and its own help pages note a roughly 15MB ceiling on the free web tools before you need the desktop app.

Foxit PDF Reader mirrors Acrobat Reader closely: excellent free highlight, comment, and fill-and-sign, no watermark, no signup, but redaction, true text editing, and merge/split all sit behind Foxit's paid Editor Pro or Business tier.

Browser-native tools are fastest for a pure highlight-and-comment pass; none of the three has a merge tool, a redaction tool, or real text editing.

Weave is not trying to be a PDF editor for jobs 2 through 5. It is built for reading a contract clause by clause, highlighting and commenting in the browser with nothing uploaded, the strongest privacy option here for job 1. Use one of the tools above for text editing, redaction, signing, or merging, and see Free Alternatives to Adobe Acrobat for Contract Markup for the markup side specifically.

The privacy test: watch where the file actually goes

Six of the eight tools above upload your file to a server before they can process it. That is fine for a blank template; it is worth pausing on for a contract naming a person, a salary, a bank account, or an address, because that document is personal data under Indian law the moment it identifies someone, not just when it is marked "confidential." Section 8(5) of the Digital Personal Data Protection Act, 2023 states the obligation plainly:

"A Data Fiduciary shall protect personal data in its possession or under its control, including in respect of any processing undertaken by it or on its behalf by a Data Processor, by taking reasonable security safeguards to prevent personal data breach."

Read the full Act on MeitY's official site. Section 8(5) is written for organisations, but the underlying question applies just as much when you personally pick which website to hand a contract to: an unfamiliar "free PDF tool" domain is, functionally, a processor you know nothing about. Before uploading a sensitive contract to any tool marked "upload" above, run this:

1. Open developer tools (F12 on Windows, Cmd+Option+I on a Mac), click the Network tab, and clear the log.
2. Open or drag your PDF into the tool.
3. Watch for a POST request, often named upload or convert, to the tool's own domain, sized close to your file. That is your contract leaving your machine.
4. A local tool (a browser's own viewer, a downloaded desktop app, or Weave) shows little to nothing leaving at all.

This is not an abstract formality. The Supreme Court's nine-judge bench in Justice K.S. Puttaswamy (Retd.) v. Union of India, (2017) 10 SCC 1, held that privacy is a fundamental right under Article 21, part of an individual's ability "to control significant aspects of his or her life." A vendor contract with someone's salary or bank details is exactly what that reasoning protects, a real reason to run the Network tab test rather than trust a homepage's "your files are safe with us." See DPDP Act for Contracts for what this means for contracts specifically.

"Redacted" and "edited" both need verification, not trust

Redaction. A black box drawn over text is not redaction, it is a dark highlight, and the text underneath is almost always still selectable. Test any tool's "redacted" output: open the file, drag-select over the black box as if highlighting hidden text, copy it (Ctrl+C), and paste into Notepad. If real words appear, the redaction is cosmetic; only PDFgear's desktop app and Xodo's dedicated redact tool passed this cleanly in our check, and you should run it on every document, not just the first time you try a tool.

Editing. Editing an unsigned draft is fine, use whichever tool above does real in-place text changes (Sejda's web tool, PDFgear's desktop app). But never use a PDF editor to change the wording of a contract already signed by both sides, even for a typo fix. Section 63 of the Bharatiya Sakshya Adhiniyam, 2023 (which replaced Section 65B of the Evidence Act in July 2024) governs whether an electronic document is admissible as evidence, partly through a hash value that changes the instant a single character in the file is altered:

"Notwithstanding anything contained in this Adhiniyam, any information contained in an electronic record which is printed on paper, stored, recorded or copied in optical or magnetic media or semiconductor memory... shall be deemed to be also a document... and shall be admissible in any proceedings, without further proof or production of the original," subject to the conditions and certificate requirements in the section.

Read it on Indian Kanoon. The takeaway is not that editing a PDF is illegal, it is that a signed contract's file should be treated as final; if terms genuinely need to change, that is what an amendment clause is for, not a re-opened PDF.

Red flags when choosing (or trusting) a free PDF tool for a contract

Normal	Red flag	Why it matters
A specific free-tier limit is stated (pages, tasks/hour, size)	"Unlimited free forever," no fine print	Vague claims get walked back after signup, or the limit only appears once you hit it
Redaction is labelled "permanent deletion" and the method is explained	"Redact" shown only as a black-box screenshot	If the vendor cannot explain how it removes text, assume it does not
Upload is disclosed, with a stated deletion window	No privacy statement, or one that appears only after upload	You should know before you upload, not after
The domain matches the tool's known brand	An unrelated or freshly registered domain, found via an ad	Free PDF tool sites are a common malware vector
No credit card required for the free tier	Card demanded "to verify you're human"	Usually means an auto-billing trial, not a free tool
Signature is labelled a drawn or typed image	Marketed as a "legally binding digital signature"	Overstates the signature's legal weight; see the FAQ below

An amendment clause that stops you needing to "edit" a signed PDF

The best fix for the editing risk above is often not a better tool but a better clause, so nobody is tempted to just open the signed PDF and change a number.

Bad: "This Agreement may be amended at any time."

This says nothing about form. It does not require writing or both sides' signatures, and gives no guidance on someone editing a copy of the signed PDF and calling it the new version, exactly the temptation this article is about.

Better: "This Agreement may be amended only by an instrument in writing signed by the authorised representatives of both Parties. No change made by altering the text of a previously executed copy of this Agreement, without such a signed written instrument, shall have any legal effect."

The rewrite requires a fresh, separately signed writing for any change, and says explicitly that editing the old signed file does not count. That second sentence is the one most template amendment clauses skip, and it directly answers "can I just fix this in the PDF" with a documented no.

Which tool to actually use, by job

• Highlight and comment before a call: your browser, or Weave for clause-by-clause work with nothing installed or uploaded.
• Edit the wording of an unsigned draft: Sejda (in-place, mind the 3-tasks-per-hour cap) or PDFgear's desktop app (unlimited, offline).
• Genuinely redact one sensitive line: PDFgear's desktop app or a single use of Xodo's redact tool, then run the copy-paste test.
• Fill and sign a form: Xodo, PDFgear, Sejda, PDF24, or Foxit Reader; none of the free image signatures are "certified" digital signatures.
• Merge annexures or split a schedule: Xodo or PDF24, both fast and free for this.
• One-off, offline, no internet: LibreOffice Draw, accepting marks may not survive the trip to another viewer.

FAQ

Which free PDF editor lets me actually change the text, not just add a comment box? Sejda's web tool and PDFgear's desktop app both do real in-place text editing for free. Xodo, PDF24, and PDFgear's own web version only place a text box over the page, not the same as changing the underlying text.

Is a black box over text in a free PDF tool real redaction? Not automatically. Many tools draw a rectangle on top of the text, which stays selectable underneath. Copy the area under the box and paste into Notepad; if real text appears, it was never removed.

Which free tool keeps my contract fully private? Anything local: a browser's built-in viewer, the LibreOffice, PDFgear, or PDF24 desktop apps once downloaded, or Weave, which processes the file in your browser without uploading it. Run the Network tab test in this guide rather than trust a homepage claim.

Can I edit a contract PDF after both sides have signed it? You should not, even for a small correction. A signed contract is meant to be final; editing the file directly creates a document whose hash no longer matches the original, which matters if it is ever produced as evidence under Section 63 of the Bharatiya Sakshya Adhiniyam, 2023.

Is a signature added with a free tool legally valid in India? Generally yes for forming a contract, since Indian law recognises electronic records broadly, but a drawn or typed image signature is a different legal category from a certificate-backed digital signature. See Electronic Signature Validity in India for which situations need the stronger kind.

Sejda says "3 tasks per hour" on the free plan. What counts as a task? Each edit, merge, split, or export you run counts as one; three of them and you wait an hour or upgrade. For a single contract this rarely bites; for repeated edits on the same file, PDFgear's desktop app has no such counter.

---

This comparison is based on hands-on testing of the free tiers listed, as of September 2026. Limits, pricing, and features on any of these tools can change without notice, so re-check what matters to you before relying on it. It does not tell you whether a redaction meets a specific regulatory requirement, whether an edit affects a contract's enforceability, or whether a signature meets the bar a particular transaction needs; those depend on the document and often need a lawyer's judgment, not just the right software.