CoA Checker
CoA Checker: grade a peptide certificate of analysis in seconds
Know what you are really buying. Free.
Upload a certificate as a PDF and get a plain-language breakdown: what the document actually proves, what is missing from it and what to verify with the laboratory. The file is processed in your browser.
Reviewed by: Mgr. Martin Rehúcy, pharmacist · Updated
- Free, no sign-up
- Processed in your browser
- Educational tool, not a certification
- PDF from any laboratory
Final grade
Traceable, analytically thin
An educational reading of what the certificate documents.
The certificate is processed entirely in your browser using the PDF.js library. The file is not uploaded, not stored and never leaves your device.
Processing the certificate
- Reading text from the PDF
- Evaluating criteria
- Calculating the grade
What is a certificate of analysis (CoA)
A certificate of analysis is a document in which a laboratory summarises the test results of one specific batch: what was measured, when and by which method. For a research peptide it should state the batch number, the date, a named laboratory, HPLC purity with a chromatogram and identity confirmation by mass spectrometry.
A CoA is not a quality certificate and not a permit to sell. It speaks about the documentation of a batch, not about the substance being good or safe. That is why it pays to read it item by item: a purity figure without a chromatogram is a claim, not evidence, and an analysis without a batch number belongs to some vial, not to yours. The table below summarises what a complete certificate contains and which values are common in practice.
What a complete peptide certificate of analysis contains
| Parameter | Method | Typical value or form |
|---|---|---|
| Purity | RP-HPLC, UV detection at 214 to 220 nm | Typically 98 % or higher, stated to two decimals and backed by a chromatogram |
| Identity | LC-MS or LC-HRMS | Measured mass consistent with the theoretical mass of the sequence |
| Batch, date, laboratory | Report header | Batch number matching the label, analysis date under 12 months old, a named laboratory |
| Verification key | Laboratory register | A code or QR with which the laboratory confirms it really tested the batch |
| Endotoxins | LAL test per USP <85> | Below 1 EU/mg for routine research, below 0.1 EU/mg for sensitive models |
| Water content | Karl Fischer titration | Typically below 10 % |
| Peptide content and counterion | Amino acid analysis, ion chromatography | Peptide content typically 70 to 90 % by weight, TFA or acetate 5 to 15 % |
How it works
The tool reads the certificate PDF in your browser, compares it against 13 criteria and returns a grade from A+ to F together with the full calculation. It takes a few seconds and needs no sign-up.
- 01
Upload
Choose the certificate PDF. The file never leaves your device.
- 02
The tool reads it
Batch number, purity, laboratory, date and other parameters are extracted from the document.
- 03
You get the breakdown
A grade from A+ to F plus the full calculation: what was found, what is missing and why it matters.
What the grade means and what it does not
A certificate of analysis summarises the tests performed on one specific batch. The grade describes how complete and verifiable the documentation is, not that the substance is good or safe. The tool cannot verify whether the stated numbers are true. For decisions that matter, request the original laboratory report and verify the batch directly with the laboratory.
The full scoring equation
Nothing in the grade is an estimate. This is the whole table it is calculated from.
Traceability
30- Batch number 10
- Date of analysis 8
≤ 12 mo. → 8 · ≤ 24 mo. → 4 · > 24 → 0
- Sequence or CAS 6
- Molecular weight 6
Independence and verifiability
25- Named laboratory 10
- Independent third party 8
- Verification key 7
Purity
25- Purity figure 10
≥ 99 % → 10 · ≥ 98 → 8 · ≥ 95 → 5 · ≥ 90 → 2
- Chromatogram or integration table 10
- Method description 5
Quantity and identity
20- Measured vial content 8
- Identity by mass spectrometry 8
- Theoretical versus measured mass 4
Beyond standard
+20- Endotoxins +6
< 0.1 EU/mg → 6 · < 0.5 → 5 · < 1 → 4 · ≥ 1 → 1
- Peptide content by weight +4
- TFA or acetate counterion +3
- Water content +3
- Sterility or bioburden +2
- Heavy metals or residual solvents +2
Penalties
- Suspiciously round purity. A real measurement gives 99.861 %, not a whole number. -8
- Analysis older than two years. -10
- No independent third party, the analysis rests on the seller’s word alone. -12
- The date of analysis precedes the manufacturing date. -10
Caps
- Without a batch number the score cannot exceed 59 points, the certificate cannot be tied to your vial. 59
- Without a named laboratory the score cannot exceed 64 points. 64
- Without a stated purity the score cannot exceed 44 points. 44
Grading scale
The grade is the sum of points for 13 criteria after penalties and caps. A+ stands for a pharmaceutical level of documentation, F for a document with no evidentiary value.
| Grade | Points | Meaning |
|---|---|---|
| A+ | 105+ | Pharmaceutical level of documentation |
| A | 95 – 104 | Everything essential, including chromatogram and identity |
| B | 82 – 94 | Solid certificate, one layer of evidence missing |
| C | 68 – 81 | Traceable and independent, but analytically thin |
| D | 54 – 67 | Serious gaps, the essentials cannot be verified |
| E | 40 – 53 | Document with no evidentiary value |
| F | 0 – 39 | Unusable or suspicious |
What practice shows in 2026
Publicly available documentation from peptide vendors differs by orders of magnitude: from five separate tests per batch to no certificate at all. The figures below come from our September 2026 survey.
- 878
- published laboratory documents reviewed across 9 peptide vendors
- 8 of 17
- brands checked publish no certificates at all, or only behind a browser script
- 5
- separate tests per batch in the deepest documentation on the market: HPLC, endotoxins, heavy metals, sterility and fentanyl screening
- 13
- criteria and 120 points make up the grade in this tool
Source: internal survey of the published documentation of 9 peptide e-shops, Molequa, 17 September 2026. The figures describe the extent of documentation, not the quality of the substances, and none of it was independently verified.
Frequently asked questions
Everything on this page is educational. It exists to help you understand what you are buying.
What does this tool do?
It reads a certificate of analysis in PDF and tells you how complete and verifiable the documentation is. It looks for thirteen things: batch number, date, laboratory, purity, chromatogram, identity confirmation and more. For each one it shows whether it was found in the document and why it matters.
What is a certificate of analysis?
A document in which a laboratory summarises the tests performed on one specific batch. It is not a quality certificate and not a permit to sell. It states only what was measured, when and by which method.
How long does it take?
A few seconds. The certificate is never uploaded anywhere; it is processed in your browser, so the speed depends only on your device.
Does this tool certify the product or the supplier?
No. It grades the quality of the documentation, not the quality of the substance. A high grade means the certificate is complete and verifiable, not that the material is good. A low grade means the document does not give you enough information, not that the product is bad.
Can I upload a photo of the certificate from my phone?
Yes. Besides PDF the tool also accepts PNG and JPG, so a screenshot or a photo works. The text is recognised from the image inside your browser, so the image is not uploaded anywhere either. Quality decides the outcome: a sharp screenshot is reliable, a photo taken at an angle or in poor light may not be readable. If too little text can be extracted, you get an explanation instead of a grade.
Are my certificates or results stored?
No. The file never leaves your device, nothing is sent to a server and no result is saved. Once you close the page, nothing remains anywhere.
Why did my certificate get a lower grade than I expected?
Most often the chromatogram, the mass spectrometry identity confirmation or a verification key is missing. The phrase "chromatogram available on request" does not count, because evidence you do not hold is not evidence. The full calculation is shown under the grade, item by item.
Is it really free?
Yes. The tool is free, needs no sign-up and has no limit on how many certificates you check. There is nothing to pay later either, because there is nothing to bill: the whole calculation runs in your browser, not on our server.
Related tools and documentation
The certificates for every batch in our range are publicly downloadable, so you can grade them with the same tool.
- Technical documentation and CoA library Certificates of analysis for all batches as PDF, with batch number and test date.
- Research peptides with a certificate for every batch Peptide catalogue, each batch has its own independent laboratory report.
- Frequently asked questions on orders and documentation Storage, shipping, batch documents and research use.
- Peptide calculator Solution concentration from lyophilizate mass and solvent volume for laboratory work.
